An oft-repeated objection to the Trinity is that the Scriptures provide no theological basis upon which one can build a case for the Trinity. Further, those unfamiliar with Christian origins and the historic development of Christian doctrines propose that the initial followers of Christ were not Trinitarian, even in some nascent form. Therefore, prior to interacting with the Muslim perception of the Trinity and the challenges involved with presenting the Trinity to Muslims, it would beneficial to define an orthodox doctrine of the triune Godhead.
This goal will be accomplished by first examining scriptural evidence for the Trinity; that is, the designation that the Father is God, the Son is God, and the Holy Spirit is God. Second, this is accomplished through a survey covering major developments in Trinitarian thought during the first four centuries of church history. The resulting orthodox definition of the Trinity will synthesize the contributions of revelation and history.
Part I: The Scriptural Case
Scriptural evidence for the Triune God
The particular terminology applied to the doctrine of the Trinity is extra-biblical; however, the concept is not. Despite the fact that Scripture lacks any explicit discussion of Trinitarian formulae, it does implicitly teach this schema. Additionally, Scripture expresses in very clear terms that the members of the Godhead are all full deity.
Plurality within Unity
When discussing the plurality within unity implied in the Old Testament, much is made of Genesis 1:26, a text utilizing the Hebrew word Elohim. This passage, Genesis 1:26, clearly portrays Elohim as an example of plural-unity. The passage reads: “Then God said, Let Us make man in Our image, according to Our likeness…” The significance of this passage is in the fact that God refers to Himself in the plural while declaring there is but a single image in which man is to be made.
Some anti-trinitarians would object to this use, noting that Psalm 82:6 translates Elohim as “gods.” Therefore, Elohim must be seen as supporting a plurality of “gods” rather than a single God. It is true that Elohim is accurately translated as “gods” in Psalm 82:6; however, when Elohim is used as a name for God it is ontologically in the singular sense. There are others who believe that the “Us” and “Our” statements could not be representative of the Trinity, instead believing that this plural terminology is “plural of majesty” construct. Simply speaking, this means that a person in a position of royalty in an ancient culture would, on occasion, speak of himself in the plural form. Therefore, Genesis 1:26 should be seen as nothing more than a regal pronouncement.
Wayne Grudem argues against this position, pointing out that, “In Old Testament Hebrew there are no other examples of a monarch using plural verbs or plural pronouns of himself … so this suggestion has no evidence to support it.” Similarly, O.T. Allis notes that while Elohim is a plural form, it is used in a singular sense throughout the Old Testament when referencing the true God of Israel. Further, there is no hint of any polytheistic, conceptual framework existing in the author of Genesis’ mind. The Hebrew conception of God was exclusively monotheistic and entirely unique among the ancient near eastern religions.
John Sailhammer also believes Genesis 1:26 to be an allusion to the triune nature of God. His conclusion is based upon the fact that God created a plurality of genders in His image, which is but a single image. This reference would cast the image of God as a plural unity similar to the human male-female relationship in creation. Speaking to this very topic, Kevin Vanhoozer states, “In marriage there is a recognition of both sameness (one flesh) and otherness (two distinct persons). ‘This is a great mystery’ (Ephesians 5:32) – great enough, perhaps, to illustrate the triune identity...” The evidence is clear, the reference in Genesis 1:26 to Elohim is not a plurality of gods but a reference to a single God, a single God who possesses plurality within unity. This is made apparent by the fact that a plurality of persons (male and female) coming together as one flesh is the ultimate expression of the image of Elohim.
One of the most compelling Trinitarian Old Testament texts is found within the confession of Hebrew monotheism, the Shema. The passage from which the Shema is taken, Deuteronomy 6:4, reads “Hear, O Israel! The LORD is our God, the LORD is one!” The Hebrew word used in this text for “one” is echad. While the word is accurately translated as “one,” it does not imply a position of isolation. Instead, echad stresses the uniqueness, as well as the unity, of Yahweh. The intent of the passage is to provide a clear distinction between the monotheism of Israel and the polytheism of the surrounding nations. An example of unity is located in Genesis 2:24, when Adam and Eve are described as becoming “one (echad) flesh.” One should note that, while they became “one,” Adam and Eve did not lose their individuality. In light of this material, one could not propose that the Old Testament portrays God as a monad.
The possibility of plurality existing in a monotheistic Godhead was an active topic in pre-Christian Jewish theology. A text that inspired much of this debate is found within Daniel’s book of prophecy. In Daniel 7:9, a plurality of thrones exists in heaven, all of which, the text proposes, belong to Yahweh. The text reads, “I kept looking until the thrones were set up, and the Ancient of Days took His seat…” In the passage there are multiple seats of power (thrones), yet a single being of power (the king). N.T. Wright, commenting on pre-Christian Judaism, points out that, “Within the most fiercely monotheistic of Jewish circles…there is no suggestion that ‘monotheism’ or praying the Shema, had anything to do with the numerical analysis of the inner being of Israel’s God Himself.” The insistence upon monadic monotheism resulted from the teachings of post-Christian rabbis. This concept was stressed in an attempt to curb what some perceived as a violation of biblical monotheism. Historically speaking, there existed speculative, pre-Christian, Jewish theology seeking to understand Scriptures’ implicit plurality within unity. It was only after the advent of Christ that there was a personal being besides the Father who received worship due solely to Yahweh.
In summary, within the Old Testament allusions to unity within plurality clearly exist. While not stated as explicitly as in the New Testament or resulting creeds, the prospect of a pre-Christian Trinitarian theology is presented by terminology and grammar utilized throughout the Old Testament. After reviewing the evidence, N.T. Wright concludes that: “The oneness of Israel’s God, the creator, was never an analysis of God’s inner existence, but always a polemical doctrine over against paganism and dualism. It was only with the rise of Christianity…that Jews in the second and subsequent centuries reinterpreted ‘monotheism’ as the numerical oneness of the divine being.” Clearly, one cannot propose that the Old Testament lacks any notion of God’s plurality within unity.
The Father is God
Throughout Scripture, the Father is acknowledged as a full deity. Because this fact is recognized as beyond question, a mere sampling of biblical evidence will be presented. In Romans 1:7, Paul greeted the church at Rome saying, “Grace to you and peace from God our Father and the Lord Jesus Christ.” Paul made a distinction between the Son and the Father, yet recognizes the divinity of both. Similarly, in his letter to the Galatians, he wrote: “Paul, an apostle not sent from men nor through the agency of man, but through Jesus Christ and God the Father, who raised Him from the dead…” Paul once again acknowledged the full deity of both Christ and the Father, while at the same time recognizing their distinct economic functions. In the Gospel of John, Jesus identifies the Father as God, while also admitting His own deity, stating: “Not that anyone has seen the Father, except the One who is from God; He has seen the Father.” Undoubtedly, the Fatherhood of God is assumed throughout Scripture.
The Son is God
Muslim critics of the New Testament object to the deity of Jesus Christ on the basis that Christ nowhere claimed to be God in the flesh. Though Jesus never said, “I am God,” He did use other language which inescapably leads to the conclusion that Christ believed He was God in the flesh. What follows is a brief survey of pertinent passages establishing the deity of Jesus Christ.
First, in John 17:5, Christ claims to share the glory of the Father. He says, “Now, Father, glorify me together with Yourself, with the glory which I had with You before the world was.” Jesus Christ was referencing Isaiah 42:8: “I am the LORD, that is My name; I will not give My glory to another…” If Yahweh does not share His glory, and Christ claims to share Yahweh‘s glory, He equates Himself with the Father.
Second, in John 5, Christ makes a series of claims that placed Him on the same level as the Father. John 5:18 reads, “For this reason therefore, the Jews were seeking all the more to kill Him, because not only was He breaking the Sabbath, but He was calling God His own Father, making Himself equal with God.” In the same passage, Christ raised people from the dead and claimed to be the giver of life, an attribute the Old Testament attributes solely to God.
Third, Jesus Christ claimed to be the promised Messiah. During His trial Christ was asked, “Are You the Christ, the Son of the Blessed One?” Jesus responded by saying, “I am; and you shall see the Son of Man sitting at the right hand of Power, and coming with the clouds of heaven.” According to the prophet Isaiah, the Messiah would be God. Isaiah writes that, “His name will be called Wonderful counselor, Mighty God (el’ gibbor), Eternal Father, Prince of Peace.” Some scholars allege that Isaiah was teaching that the Messiah would be a god-like hero, not God in the flesh. While the word el’ in a plural form can refer to a mortal man, Isaiah only used this word as a designation for God. In the context of the passage, the reader is confronted with a contrast between the Messiah‘s humanity as a child (yeled) and His deity as the heroic God (el gibbor), the Messiah of His people. Therefore, based upon the context, this Being is not god-like but is in actuality the hero God. Additionally, in Christ’s response at His trial, He called Himself “The Son of Man.” This title refers to an Old Testament prophecy found in Daniel regarding the coming Messiah. Daniel 7:13-14 reads: “…behold, with the clouds of heaven One like a Son of Man was coming, and He came up to the Ancient of Days and was presented before Him. And to Him was given dominion, Glory and a kingdom that all the peoples, nations and men of every language might serve Him, His dominion is an everlasting dominion which will not pass away; and His kingdom is one which will not be destroyed.” This designation, Ancient of Days, was previously used in Daniel 7:9-13 for God the Father. Thus, according to the prophet Daniel, the Messiah (Son of Man) would be distinct from the Ancient of Days yet fully share his deity and attributes.
The Spirit is God
The biblical text not only accords full deity to the Father and Christ, but to the Holy Spirit as well. For instance, in Matthew 28:19, the role of the Spirit in baptism is identical with that of the Father and Son. In Acts 5:3-4, Peter equated Ananias’ lie to the Holy Spirit as being a lie to God. 1 Corinthians 2:10-11 portrays the Spirit as having the same omniscience as God the Father. This aspect of God is also seen in the Old Testament writings of the Psalmist. The Psalms declare that the Spirit shares the omniscience, as well as the omnipresence, of God the Father. In terms of Scriptural presentation, the Holy Spirit is afforded similar, if not identical, divine attributes and activities as the Father and the Son. As a result, He should be considered as full deity.
Part II: The Development of Early Trinitarian Thought
Any Trinitarian exploration must begin with Scripture, followed by a survey encompassing the historical developments pertaining to the Trinity. This logic is based upon a series of observations: First, “What we today consider important to say about Christ is strongly influenced by what we believe the early church thought important to say.” All contemporary, theological dialogue takes place in light of a long history of theological struggle. To ignore this fact is to assume that theology occurs within a vacuum, which it does not. Theology develops and contours itself in response to the questions being asked during a given time period. Second, the issues that dominated the Patristic period matter because, whether consciously acknowledged or not, the way Christians read Scripture has been influenced by formulas and decisions birthed in the early church. Last, in an attempt to contextualize the Trinity to Muslims, one must start with the early church and her Trinitarian growing pains. Many objections to the Trinity are based upon Muhammad‘s encounters with heretical understandings of the triune Godhead. The Qur’an states that men have invented doctrines in an attempt to distort or to “go beyond” the bounds of their religion. The charge insinuates that true worshippers of God were not initially Trinitarian, but developed the Trinity in an attempt to blend polytheism with monotheism.
The Scriptural case for a belief in three persons, all God, has already been presented. The doctrine of the Trinity is not an attempt to transcend the bounds of the Scriptures’ straightforward teaching. According to Alister McGrath, the Trinitarian formula resulted from answering the following two questions: “Who and what must God be if he was able to become incarnate in Jesus Christ? What must be true about God, if it is true that Jesus Christ is divine?” Moreover, the doctrine of the Trinity does not originate within the bounds of the fourth century. The New Testament church always afforded the triune God His due worship. J. Scott Horrell has noted that, “It can never be said that the early church was not Trinitarian. The threefold experience of the personal God is densely woven throughout the New Testament.” In addition, while the vocabulary used to describe the Trinity required some time to develop, this extended time frame is not born from a lack of Trinitarian conviction. The early church lacked a conceptual basis upon which to give full disclosure concerning the triune God’s substantive hierarchy. Plainly speaking, “Neither Jewish theology nor Greek philosophy provided the conceptual frameworks, much less the right words, needed to express what the church fathers were seeing in the Bible’s witness of God as Father, Son, and Holy Spirit.” The early church faced a linguistic disadvantage when expressing the Trinity to the world around her. Regardless of this difficulty in language, the church needed descriptions and defenses of Biblical doctrine in order to survive.
A progressive development of Trinitarian doctrine based upon questions being asked of the church occurred during the first few centuries of history. This doctrinal evolution was a result of increasingly complex answers to questions the church faced concerning the triune God. The inquiries posed to the church resulted from the influences of Gnosticism, Platonism, and Neo-Platonism (a system which had a dramatic influence upon the theological landscape of Islam). What becomes apparent is that while the basis for theology – revealed Scripture – does not change, the complexity and clarity of doctrines changes as the community of faith systematizes what is demonstrated within the revealed text.
The Apostolic Fathers
The impetus to examine the Scriptural representation of the triune God, and to express this mystery in creedal form, did not arise for nearly a century after the completion of the New Testament. Admittedly, no explicit Trinitarian doctrine was offered by the Apostolic Fathers; however, the triadic schema is still implicit in their writings. For example, in his first letter Clement (c. 45-99) wrote, “Have we not one God and one Christ? Is not the Spirit of grace, which was poured out upon us, one? Is not our calling one in Christ?” This triadic schema appears again in the same letter with the phrase, “For, as God lives, and as the Lord Jesus Christ and the Holy Ghost live…” A similar formulation appears again in the works of Ignatius (c. 50-117). In his Letter to the Magnesians, Ignatius writes, “…[p]rosper…in the Son, and in the Father, and in the Spirit…Be subject to the bishop, and to one another, as Jesus Christ to the Father, according to the flesh, and the apostles to Christ, and to the Father, and to the Spirit…” The formula appears again in his Letter to the Ephesians. In section thirteen, Ignatius addressed the issue of false doctrine, and praised those in Ephesus for resisting false teachers. Ignatius utilized the triadic concept by likening the Father to stones upon which a building is built; Christ, through the cross, is the instrument of building, and the Holy Spirit is the rope by which we ascend unto God through faith. Throughout the remainder of the letter Christ is addressed as God, and prayer to Him is assumed. While not clearly described, the Apostolic Fathers recognized, at least in the redemption of man, the triune nature of God.
First-century letters were not penned to provide a codified theological statement of faith; rather, they were written to address contemporary concerns. The question of Trinitarian ontology and relational action was rarely, if ever, clearly asked or answered. Therefore, the apostolic writings did not substantially advance Trinitarian theology; instead, they served to synthesize the evidence presented in Scripture. This does not mean that they were explicitly Trinitarian; however, recognition of God’s plural unity was apparent throughout their writings.
With the dawn of the second century came the rise of the Apologists, and a new era in Trinitarian discourse. The needs of the period demanded further exploration into the nature of God. Confronted by a pagan society, charges of atheism, and the challenge of Greek philosophy, the Apologists sought to explain the nature, function, and interaction of the Godhead. This was attempted in part to distinguish the God of the Christians from pagan gods. Specifically, the Apologists made the first attempt to provide a detailed explanation of the relationship between the Father and the Son. The single greatest contribution to the Trinitarian conversation by the Apologists was the designation of Christ as the Logos. Utilizing John’s concept, the Apologists capitalized on a notion already pervading the philosophy of the day. Craig Blomberg explains, “Logos was a widely used term to refer to the way that God or the gods revealed themselves and communicated with humankind.” In a very general sense, Logos “refers to a spoken word, with emphasis on the meaning conveyed, not just the sound.” However, John’s meaning is clearly designed to transcend this term’s functional usage, created instead to delve into the ideas of current and past philosophical discussion. The Logos epitomizes the manner in which Christ is to be equated with God.
Justin Martyr (100-165) was the apologist who most frequently utilized the Logos concept. According to Justin, the Logos “being Word and first-begotten of God, He is also God.” Additionally, in his Dialogue with Trypho, Justin declares that the Logos “… is adorable, He is God.” Therefore, “the Logos is one with God, yet the Logos is entirely distinct, as a ray of light is distinct from the sun.” Perhaps Justin’s view is best represented by the following analogy: “When we give out some word, we beget the word; yet not by abscission, so as to lessen the word [which remains] in us … just as we see also happening in the case of a fire, which is not lessened when it has kindled [another], but remains the same; and that which has been kindled by it likewise appears to exist by itself, not diminishing that from which it was kindled.” This distinction in number does not mean there is a division of essence. The “birth” of the Logos represents a distribution of God, but not a severing of the divine nature.
Another noteworthy work, A Plea for the Christian, was written by Athenagoras of Athens (c. 133-190) to defend the church against the charge of atheism. He wrote: “We are not atheists … we acknowledge one God, uncreated, eternal … we acknowledge also a Son of God. Nor let anyone think it ridiculous that God should have a Son. For though the poets, in their fictions, represent the gods as no better than men, our mode of thinking is not the same as theirs … the Son of God is the Logos of the Father … the Father and the Son being one.” Not only did Athenagoras dispute the charge of atheism, but he also landed a serious blow to the claim that Christians believe Christ to be the biological Son of God.
For some within this period, including Irenaeus of Lyon (c. 115-199), salvation depended upon this distinction. Within Irenaeus’ theological system, the Father literally extrapolates the Son and Spirit from within Himself. According to Irenaeus, man’s redemption is founded upon the tri-unity of God; “…regeneration proceeds through these three points: God the Father … through His Son by the Holy Spirit.” As a result, salvation is impossible without the work of the triune God.
In summary, the Apologists strove to explain God’s plurality within unity through the conception of the Logos. All endeavored to do so, while at the same time maintaining that a distinction between the Father and Logos in no way divides the divine essence. Furthermore, they attempted to use imagery that stressed the eternal generation of the Son, rather than any type of origination. As fruitful as this century of discourse was, an entire formula of Trinitarian orthodoxy would not be adopted as the rule of faith until the fourth and fifth centuries.
Perhaps the most prolific pre-Nicene Trinitarian developments resulted from the works of Tertullian (c. 160-225). He was the first person to use the Latin word trinitas  in describing the Godhead. The development of his terminology came as a result of his attempt to defend the personhood (persona) of the Trinity‘s members without dividing their essential substance (substantia). The language Tertullian employed in describing the triune God is borrowed from the popular argot of his era’s legal system.
In his work Against Praxeas, Tertullian explained his use and understanding of the language he implemented in describing God’s tri-unity. Tertullian wrote, “I testify that the Father, the Son, and the Spirit are inseparable from each other… My assertions is that the Father is one, the Son is one, and the Spirit is one – and that they are all distinct from each other.” It was his goal to combat the patripassianism  put forth by Praxeas. In order to demonstrate that this form of modalism was false, Tertullian used a series of images from nature. Tertullian wrote, “… the Son is a prolation from the Father, without being separated from Him. For God sent forth the Word, as the Paraclete also declares, just as the root puts forth the tree, and the fountain the river, and the sun the ray.” This type of language provided a foundation for contemporary Trinitarian discourse.
Despite his linguistic contributions to Trinitarian theology, Tertullian’s terminology was not warmly received by the church at large for a variety of reasons. First, his concepts were largely material in nature. An example of this “material” conception is Tertullian‘s description of the Trinity in Latin, una substantia, tres personae. The Greek-speaking church initially questioned the orthodoxy of such a statement. As time would tell, it was not that his concepts were heretical, but rather that the language barriers between Greek and Latin inhibited lines of theological communication. Second, his eventual conversion to Montanism  caused many to look upon him as a heretic. Regardless of these issues, his language in describing the triune God set the stage for what would be discussed at Nicaea.
The Council of Nicaea
Throughout the second and third centuries, the works of the Apologists served to engage both the church and her critics in dialogue explaining the nature of the Christian God. Despite the accomplishments of previous centuries, the fourth century brought with it seeds of controversy. Lewis Ayers proposes that the following question was the impetus for the fourth century Trinitarian controversy: “How does one understand the distinction between God and Word, Father and Son: is this the distinction of two separate beings?” The answer to this query introduced a standard for orthodoxy which has remained virtually unchanged to this day.
In the midst of turbulence in which the church found itself at the start of the fourth century, one controversy emerged as more portentous than the rest. Sparked by the works of an Alexandrian presbyter named Arius (AD 250-336), the issue that took center stage became known as the Arian controversy. According to Arius, Christ was not unbegotten; that is to say, there was a time when He did not exist. Arius writes of the Son, “He is neither eternal nor co-eternal nor co-unbegotten with the Father…” Arius believed that the doctrine of eternal generation would render God divisible and composite. The goal in Arius’ writings was not to challenge orthodoxy, but rather to uphold it in the face of teachings he believed were tantamount to polytheism. After a series of letters and local Egyptian councils, the church was left with no choice but to confront Arius at Nicaea. The council, convening from May to July AD 325, was attended by approximately 300 bishops. No official description of the proceedings exists. However, from fragmentary accounts one may ascertain that much of the discussion surrounded the terms homoiousios (like substance), and homoousios (same substance). It was the latter term that was in the Nicene Creed: “We believe in one Lord, Jesus Christ, the only Son of God, eternally begotten of the Father, God from God, Light from Light, True God from True God, begotten, not made, of one being with the Father…” Immediately following the council, Arius received a surge of support which lingered for a few centuries. The struggle for theological clarity born in the fourth century was not a result of doctrinal confusion, per se. It was a struggle principally centered on linguistic and semantic differences rather than substantively differing doctrines.
Gregory of Nyssa
Gregory (c. 335-386) penned his work On Not Three Gods in response to the claim that Christians worship three gods. In the text, he confronted those failing to acknowledge a distinction between the conceptual persons of the Trinity and the linguistic descriptions of those persons. In effect, he accomplished what Tertullian could not. According to Gregory, the seemingly three separate works of the Godhead only appear as such; they are actually a single work flowing from a single essence. Gregory summarized this position by describing the power and activities of God as, “issuing from the Father as from a spring, being brought into operation by the Son, and perfecting its Grace by the power of the Spirit.” While Gregory did employ a variety of analogical and descriptive terminology in assessing the power and action of the Godhead, he in no way conceived of a division in their essence. For him, the Godhead is not a partnership, but a unity.
The Trinity is most clearly expressed in the works of Augustine of Hippo (354-430). Augustine describes the Father and the Son as distinct from one another, yet entirely unified when he writes: “So the Father and the Son are together one being and one greatness and one truth and one wisdom. But the Father and the Son are not both together one Word, because they are not both together one Son.” Continuing this pattern of thought he writes, “The Word, therefore, the only-begotten Son of God the Father, is in all things like the Father and equal to the Father, God of God, Light of Light, Wisdom of Wisdom, Essence from Essence. He is wholly what the Father is, but not the Father; for the one is Son the other is Father.” Augustine‘s theological contributions transcend even this commentary. In his book of Confessions, he presents a case for God‘s simplicity and immutability. In another work he states that God is three persons, yet a single essence; therefore, one should not think of three gods, but a tri-unity. Lewis Ayers has noted, “Augustine consistently and specifically rules out the idea that the divine essence is prior to the divine persons … there is nothing but three coeternal and substantial persons.”
While Augustine‘s assertions are certainly true and aid in clarifying the orthodox position, His greatest contribution to Trinitarian discourse is his use of analogy. Of all his analogies, the most valuable is his picture of love. Augustine demonstrated that love requires no less than three aspects: “When I, who make this inquiry, love anything, there are three things concerned – myself, and that which I love, and love itself.” The Father, Son, and Holy Spirit are analogous to one who loves, the one being loved, and the power of love. This analogy is useful as there is one substance, love, yet three distinct aspects of that love, all of which are necessary for love to exist.
Summary of Early Trinitarian Thought
The doctrine of the Trinity in its creedal form evolved slowly and gained clarity as time progressed. During the Apostolic period, Clement and Ignatius penned letters to remedy issues within the church. Despite the fact that each stressed the unity and deity of the individual members of the divine triad, their views were still primitive and lacked a conceptual explanation of God’s tri-unity. With the advent of the Apologists, greater attention was given to the nature of the triune Godhead. Defending the deity of Christ in the face of Greek philosophy and heretical movements, Justin Martyr and Irenaeus would utilize the Logos concept. While the Logos was beneficial in explaining the eternal nature of Christ and his procession from the Father, it would not provide the detail needed to explicate the economic nature of the triune God. It was at this juncture that Tertullian introduced terminology describing the economy of the Trinity. Tertullian’s teaching laid the groundwork for the language used within the Nicene Creed. This language would prove advantageous in combating the heretical doctrines of the presbyter Arius. Much of what the council would conclude constituted orthodoxy came as a product of the previous century’s struggle with communicating the nature of the triune God. While Nicaea  was significant in combating the heresy of Arius, the greatest expression of Trinitarian theology was yet to come in the works of Augustine. For the first time, a theologian would paint an unambiguous word picture of God’s tri-unity. Utilizing a vast array of analogies, Augustine succeeded where others had fallen short, describing the necessity of God’s triune nature. It was through his effort to synthesize the Trinitarian works of men before him that resulted in a bridging of theology between the church in the east and west. In conclusion, one cannot comprehend the historic, orthodox Christianity without examining the historical development of its doctrine of God. Such an investigation should focus upon the patristic struggle to formulate an orthodox creed that expressed the tri-unity of God without violating Christianity’s commitment to monotheism. Indeed, some of the greatest obstacles in reaching Muslims with the Gospel of the triune God can be overcome with a better understanding of history.
In summary, the doctrine of the Trinity is clearly taught within Scripture. The ensuing Trinitarian creedal formulations resulted from historical meditation upon the Scriptures. When the church was born, she eagerly awaited the return of her groom, Jesus Christ. The expectation of the early church was that Christ would return within the lifetime of those who had seen Him ministering on earth. This conviction precluded any significant theological exploration. However, the rise of various heretical groups pushed forward the development of standards for orthodoxy. Out of this theological progression came descriptions and defenses that demonstrated the coherence of a triune God. Therefore, the doctrine of the Trinity is based upon a variety of Scriptural and historical propositions that all conclusively lead to a conviction that God is one and yet triune.
 Norman Geisler, Systematic Theology Volume Two: God & Creation (Bloomington, MN.: Harvest House Publishers, 2003), 277.
 Henry Theissen, Lectures in Systematic Theology (Grand Rapids, MI.: Eerdmans, 1990), 90.
 An example of this can be seen in 1 Maccabees 10:19; 11:31.
 Wayne Grudem, Systematic Theology (Grand Rapids, MI: Zondervan, 1994), 227.
 O.T. Allis, God Spake by Moses (Phillipsburg, NJ: P & R Publishing, 1951), 9.
 John Walton, Ancient Near Eastern Thought in the Old Testament (Grand Rapids, MI: Baker Academic, 2006), 110. Cf. John Walton, Victor Matthews & Mark Chavalas, The IVP Background Commentary of the Old Testament (Downers Grove, IL: InterVarsity Press, 2000), 177.
 John Sailhammer, The Pentateuch as Narrative: A Biblical-Theological Commentary (Grand Rapids, MI.: Zondervan, 1992), 95-96.
 Kevin Vanhoozer, First Theology (Downers Grove, IL: InterVarsity Press, 2002), 67.
 Shema is the Hebrew affirmation of monotheism. See Ron Geaves, Key Words in Judaism (Washington D.C., Georgetown University Press, 2006), 75.
 William Mounce, Mounce’s Complete Expository Dictionary of Old Testament and New Testament Words (Grand Rapids, MI: Zondervan, 2006), 485.
 Sailhammer, 439.
 See especially, Larry Hurtado, One God, One Lord: Early Christian Devotion and Ancient Jewish Monotheism (Philadelphia, PA: Fortress Press, 1988).
 N.T. Wright, The New Testament and the People of God (Philadelphia, PA: Fortress Press, 1996), 259.
 Larry Hurtado, “First-Century Jewish Monotheism” Journal for the Study of the New Testament Volume 71 (1998), 24.
 E.E. Ellis, The Old Testament in Early Christianity (Grand Rapids, MI: Baker, 1992), 115-116.
 It is worth pointing out that there are other passages that seem to teach a plurality within unity. Perhaps the most compelling texts center on the “Angel of the Lord.” He not only receives worship due only Yahweh, He calls Himself Yahweh (Exodus 3:2-6). See Genesis 16:10, Exodus 14:19, 25; Joshua 5:14; Zechariah 1:12.
 Wright, 259.
 Charles Ryrie, Basic Theology (Chicago, IL: Moody Press, 1996), 60.
 Galatians 1:1.
 John 6:46.
 Deuteronomy 32:6; Isaiah 63:16, 64:8; John 20:17; Colossians 1:2.
 See Alhaj Ajijola, The Essence of Faith in Islam (Lahore, Pakistan: Islamic Publication, 1978), 183; Hammudah Abadalati, Islam in Focus (Indianapolis: American Trust Publications, 1975), 158.
 John 5:21.
 The Old Testament clearly presents the power to raise the dead as belonging to God alone (cf. Deuteronomy 32:39; 1 Samuel 2:6; Ezekiel 37:12-14; etc.), yet Christ repeatedly raised people from the dead.
 Mark 14:61-62.
 Isaiah 9:6.
 Edward Young, The Book of Isaiah: Volume I (Grand Rapids, MI: Eerdmans Publishing Company, 1997), 336.
 Ibid, 337.
 The “I AM” statements of Jesus Christ give evidence for His deity: John 6:35 (I AM the Bread of Life), 8:12 (I AM the Light), 10:9 (I AM the Door), 10:11 (I AM the Good Shepherd), 11:25 (I AM the resurrection and the life), 14:6 (I AM the Way the Truth and the Life), 15:1 (I AM the true vine). Also, Christ declared that He and the Father are one (John 10:36).
 Matthew 28:19b “…baptizing them in the name of the Father and the Son and the Holy Spirit.”
 Acts 5:3-4 “…Satan filled your heart to lie to the Holy Spirit... You have not lied to men but to God.”
 1 Corinthians 2:10-11 “…the Spirit searches all things… the thoughts of God no one knows except the Spirit of God.”
 See Psalm 139.
 Fred Sanders & Klaus Issler, ed. Jesus in Trinitarian Perspective (Nashville, TN: Broadman & Holman Academic, 2007), 84.
 Surah 4:171.
 Alister E. McGrath, Understanding Doctrine (Grand Rapids, MI: Zondervan, 1990), 169-170.
 Sanders & Issler, 45.
 Ibid, 46.
 William Rusch, The Trinitarian Controversy (Philadelphia, PA.: Fortress Press, 1980), 3.
 Clement, 1 Clement 46:6, New Advent http://www.newadvent.org/fathers/1010.htm (accessed January 10, 2008).
 Ibid, 58.
 Ignatius, Letter to the Magnesians, 13. “Study, therefore, to be established in the doctrines of the Lord and the apostles, that so all things, whatsoever you do, may prosper both in the flesh and spirit; in faith and love; in the Son, and in the Father, and in the Spirit; in the beginning and in the end; with your most admirable bishop, and the well-compacted spiritual crown of your presbytery, and the deacons who are according to God. Be subject to the bishop, and to one another, as Jesus Christ to the Father, according to the flesh, and the apostles to Christ, and to the Father, and to the Spirit; that so there may be a union both fleshly and spiritual.” Available from http://www.newadvent.org/fathers/0105.htm (accessed January 10, 2008).
 Rusch, 3.
 J.N.D. Kelly, Early Christian Doctrines (New York, NY: Harper & Brothers Publishers, 1960), 95.
 McGrath, 172.
 Craig Blomberg, Jesus and the Gospels: An Introduction and Survey (Nashville, TN: Broadman & Holman Publishers, 1997), 162.
 Frank Gaebelein (ed.), The Expositors Bible Commentary: Volume 9 – John & Acts by Tenney Merrill (Grand Rapids, MI: Zondervan, 1981), 28.
 In the pre-Christian apocryphal text, Wisdom of Solomon (7:21-22, 25-29; 9:1-2, 9; 18:4-6), wisdom is endowed with attributes unique to God. In the Targum, specifically the Targum Onqelos, the memra (Aramaic equivalent of logos) represents a direct expression of God‘s mind, and is often used in place of God‘s name. See Targum Onqelos to Exodus 4:12 and Peshahim 54.
 Justin Martyr, First Apology 63, New Advent http://www.newadvent.org/fathers/0126.htm (accessed January 12, 2008).
 Kelly, 96.
 Justin Martyr, Dialogue with Trypho 61, New Advent http://www.newadvent.org/fathers/01283.htm (accessed January 12, 2008).
 Kelly, 98.
 Athenagoras, A Plea for the Christians 10, New Advent www.newadvent.org/fathers/0205.htm (accessed January 13, 2008).
 Ibid, 7.
 Irenaeus, Demonstration of the Apostolic Preaching 7, New Advent http://www.ccel.org/ccel/irenaeus/demonstr.all.html (accessed January 13, 2008).
 Rusch, 5.
 See Dialogue with Trypho, 62.105 and First Apology 21.
 In response to the Logos doctrine of the Apologists, there developed a belief in adoptionism called Monarchianism. This system believed that the Son was just a man who was indwelt with the Spirit. In the process of writing against this heresy, Tertullian developed Trinitarian language that set the standard for subsequent generations. See: J.N.D. Kelly, 115-119.
 Literally, Trinity. “As if in this way also one were not All, in that All are of One, by unity (that is) of substance; while the mystery of the dispensation is still guarded, which distributes the Unity into a Trinity, placing in their order the three Persons – the Father, the Son, and the Holy Ghost: three, however, not in condition, but in degree; not in substance, but in form; not in power, but in aspect; yet of one substance, and of one condition, and of one power, inasmuch as He is one God, from whom these degrees and forms and aspects are reckoned, under the name of the Father, and of the Son, and of the Holy Ghost.” Against Praxeas 2.
 See especially, Apology 21.12, Against Praxeas, 25.
 Kenneth Latourette, A History of Christianity: Volume I (Peabody, MA: Prince Press, 2007), 145.
 Tertullian, Against Praxeas 2, New Advent http://www.newadvent.org/fathers/0317.htm (accessed on January 14, 2008).
 Patripassianism is a form of modalism that proposes God the Father suffered on the cross.
 Against Praxeas, 8.
 A Charismatic form of early Christianity focusing upon apocalyptic prophesy.
 Lewis Ayers, Nicaea and its Legacy (New York: Oxford University Press, 2004), 3.
 Richard Hanson, The Search for the Christian Doctrine of God (Grand Rapids, MI: Baker Academic, 1988), 6.
 Bart Ehrman, Christianity in Late Antiquity: Arius: Letter to Alexander of Alexandria (New York: Oxford University Press, 2004), 167.
 Ibid, 8.
 The creed formulated at Nicaea was not the final formulation but rather a first ecumenical effort in combating Arianism. The creed itself underwent a number of revisions in order to combat the ever changing forms of Arianism. It was amplified and found its final form at the Council of Constantinople in 381. “The Nicene Creed” New Advent. Available from http://www.newadvent.org/cathen/11049a.htm (accessed January 15, 2008).
 In 381, Theodosius I officially condemned Arianism. Henry Chadwick, The Early Church (New York: Penguin Books, 1993), 133.
 Ayers, 347.
 Ibid, 348.
 Gregory of Nyssa, Nicene and Post-Nicene Fathers: On Not Three Gods (Peabody, MA.: Hendrickson, 2004), 334.
 Ayers, 360.
 Augustine, On The Trinity 7.2.3, New Advent http://www.newadvent.org/fathers/130107.htm (accessed January 15, 2008).
 Ibid, 15:14.23
 Augustine, Confessions 4.16.28,New Advent http://www.newadvent.org/fathers/110104.htm (accessed January 15, 2008).
 Augustine, On the Faith and the Creed 9.20,New Advent http://www.newadvent.org/fathers/1304.htm (accessed January 15, 2008).
 Ayers, 381.
 Augustine, The Trinity, 9.2.2.
 Rusch, 26.
 According to Bart Ehrman, Nicaea did not entirely resolve the debate as much as “it hardened the lines of theological warfare.” Bart Ehrman & Andrew Jacobs, Christianity in Late Antiquity: 300-450 C.E. (New York: Oxford University Press, 2004), 157.
 Ibid, 27.
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