Apologetics is the discipline that deals with a rational defence of Christian faith. It comes from the Greek word apologia which means to give a reason or defence. In spite of the objections to doing apologetics in this sense from fideists and some presuppositionalists, there are important reasons to participate in the work of apologetics.

God Commands It

The most important reason to do apologetics is that God told us to do so. The classic statement is 1 Peter 3:15, which says, 'But in your hearts set apart Christ as Lord. Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect.' This verse tells us to be ready. We may never run across someone who asks tough questions about our faith, but we should still be ready to respond if someone does. Being ready is not just a matter of having the right information available, it is also an attitude of readiness and eagerness to share the truth of what we believe. We are to give a reason to those who ask the questions. It is not expected that everyone needs pre-evangelism, but when they do need it, we must be able and willing to give them an answer.

This command also links the work of pre-evangelism with Christ's place as Lord in our hearts. If he is really Lord, then we should be obedient to him as 'we demolish arguments and every pretension that sets itself up against the knowledge of God, and we take captive every thought to make it obedient to Christ' (2 Corinthians 10:5). This means we should confront issues in our own minds and in the expressed thoughts of others that prevent us and them from knowing God. That is what apologetics is all about.

In Philippians 1:7 Paul speaks of his mission as 'defending and confirming the gospel.' He adds in verse 16, 'I am put here for the defence of the gospel.' This implies that the defender of the gospel is out where he or she can encounter others and defend truth.

Jude 3 adds, 'Dear friends, although I was very eager to write to you about the salvation we share, I felt I had to write and urge you to contend for the faith that was once for all entrusted to the saints.' The people Jude addressed had been assaulted by false teachers, and he needed to encourage them to protect (literally agonize for) the faith as it had been revealed through Christ. Jude makes a significant statement about our attitude in verse 22, that we 'have mercy on some, who are doubting'.

Titus 1:9 makes knowledge of Christian evidences a requirement for church leadership. An elder in the church should 'hold firmly to the trustworthy message as it has been taught, so that he can encourage others by sound doctrine and refute those who oppose it.' Paul also gives us an indication of our attitude in this work in 2 Timothy 2:24-25: 'And the Lord's servant must not quarrel; instead, he must be kind to everyone, able to teach, not resentful. Those who oppose him he must gently instruct in the hope that God will grant them repentance leading them to a knowledge of the truth.' Anyone attempting to answer the questions of unbelievers will surely be wronged and be tempted to lose patience, but our ultimate goal is that they might come to a knowledge of the truth that Jesus has died for their sins. With so important a task at hand, we must not neglect obedience to this command.

Reason Demands It

God created humans to reason as part of his image (Genesis 1:27; cf. Colossians 3:10). Indeed, it is by reasoning that humans are distinguished from 'brute beasts' (Jude 10). God calls upon his people to use reason (Isaiah 1:18) to discern truth from error (1 John 4:6) and right from wrong (Hebrews 5:14). A fundamental principle of reason is that it should give sufficient grounds for belief. An unjustified belief is just that – unjustified.

Socrates said, 'The unexamined life is not worth living.' He surely would have been willing to add that the unexamined belief is not worth believing. Therefore, it is incumbent upon Christians to give a reason for their hope. This is part of the great command to love God with all our mind, as well as our heart and soul (Matthew 22:36-37).

The World Needs It

People rightly refuse to believe without evidence. Since God created humans as rational beings, he expects them to live rationally, to look before they leap. This does not mean there is no room for faith. But God wants us to take a step of faith in the light of evidence, rather than to leap in the dark.

Evidence of truth should precede faith. No rational person steps in an elevator without some reason to believe it will hold him up. No reasonable person gets on an airplane that is missing part of one wing and smells of smoke in the cabin. People deal in two dimensions of belief: belief that and belief in. Belief that gives the evidence and rational basis for confidence needed to establish belief in. Once belief that is established, one can place faith in it. Thus, the rational person wants evidence that God exists before he places his faith in God. Rational unbelievers want evidence that Jesus is the Son of God before they place their trust in him.

Objections to Apologetics

The most frequent opposition to apologetics is raised by mystics and other experientialists. Fideists and some presuppositionalists also raise objections of two basic kinds: biblical and from outside Scripture. An apologist for apologetics can see in the Scripture texts usually quoted against the work some misunderstandings or misapplications, which do not really show apologetics to be unnecessary.

Objections to apologetics from the Bible

The Bible does not need to be defended

One objection often made is that the Bible does not need to be defended; it simply needs to be expounded. 'The Word of God is alive and powerful' (Hebrews 4:12). It is said that the Bible is like a lion; it does not need to be defended but simply let loose. A lion can defend itself.

This begs the question as to whether the Bible is the Word of God. Of course, God's Word is ultimate and speaks for itself. But how do we know the Bible, as opposed to the Qur'an or the Book of Mormon, is the Word of God? One must appeal to evidence to determine this. No Christian would accept a Muslim's statement that, 'the Qur'an is alive and powerful and sharper than a two-edged sword.' We would demand evidence.

The analogy of the lion is misleading. A roar of a lion 'speaks for itself' with authority only because we know from previous evidence what a lion can do. Without tales of woe about a lion's ferocity its roar would not have authority. Likewise, without evidence to establish one's claim to authority, there is no good reason to accept that authority.

God can't be known by human reason

The apostle Paul wrote, 'the world by wisdom knew not God' (1 Corinthians 1:21). This cannot mean that there is no evidence for God's existence, however, since Paul declared in Romans that the evidence for God's existence is so 'plain' as to render 'without excuse' one who has never heard the gospel (Romans 1:19-20). Further, the context in 1 Corinthians is not God's existence but his plan of salvation through the cross. This cannot be known by mere human reason, but only by divine revelation. It is 'foolish' to the depraved human mind. Finally, in this very book of 1 Corinthians, Paul gives his greatest apologetic evidence for the Christian Faith – the eyewitnesses of the resurrection of Christ which his companion Luke called 'many infallible proofs' (Acts 1:3 NKJV). So his reference to the world by wisdom not knowing God is not a reference to the inability of human beings to know God through the evidence he has revealed in creation (Romans 1:19-20) and conscience (Romans 2:12-15). Rather, it is a reference to human depravity and foolish rejection of the message of the cross.

Indeed, even though humankind knows clearly through human reason that God exists, nevertheless, he 'suppresses' or 'holds down' this truth in unrighteousness (Romans 1:18).

Natural humanity can't understand

Paul insisted that 'the man without the Spirit does not accept the things that come from the Spirit of God' (1 Corinthians 2:14). What use, then, is apologetics? In response to this argument against apologetics, it should be observed that Paul does not say that natural persons cannot perceive truth about God, but that they do not receive (in Greek 'dekomai' meaning 'welcome') it. Paul emphatically declares that the basic truths about God are 'clearly seen' (Romans 1:20). The problem is not that unbelievers are not aware of God's existence. They do not want to accept him because of the moral consequences this would have on their sinful lives. First Corinthians 2:14 (NKJV) says they do not 'know' (in Greek 'gnosko') which can mean 'to know by experience'. They know God in their mind (Romans 1:19-20), but they have not accepted him in their heart (Romans 1:18). 'The fool says in his heart, "There is no God'" (Psalms 14:1).

Without faith one cannot please God

Hebrews 11:6 insists that 'without faith it is impossible to please God'. This would seem to argue that asking for reasons, rather than simply believing, displeases God. But, as already noted, God does call upon us to use our reason (1 Peter 3:15). Indeed, he has given 'clear' (Romans 1:20) and 'infallible proofs' (Acts 1:3 NKJV). Second, this text in Hebrews does not exclude 'evidence' but actually implies it. Faith is said to be 'the evidence' of things we do not see (Hebrews 11:1 NKJV). Just as the evidence that a witness is reliable justifies my believing testimony of what he or she saw and I did not, even so, our faith in 'things not seen' (Hebrews 11:1 NKJV) is justified by the evidence that God does exist. The latter evidence is 'clearly seen, being understood from what has been made' (Romans 1:20).

Jesus refused to give signs for evil men

Jesus rebuked people who sought signs; hence, we should be content simply to believe. Indeed, Jesus did on occasion rebuke sign seekers. He said, 'A wicked and adulterous generation asks for a miraculous sign!' However, this does not mean that Jesus did not desire people to look at the evidence before they believed. Even in this passage Jesus went on to offer the miracle of his resurrection as a sign of who he was, saying no signs would be given, 'except the sign of the prophet Jonah' (Matthew 12:39-40; cf. Luke 16:31).

Jesus offered his miracles as a proof of his messianic office. When John the Baptist inquired whether he was the Christ, Jesus offered miracles as proof, saying: 'Go back and report to John what you hear and see: The blind receive sight, the lame walk, those who have leprosy are cured, the deaf hear, the dead are raised, and the good news is preached to the poor' (Matthew 11:4-5). And when replying to the Scribes, he said: '"But that you may know that the Son of Man has authority on earth to forgive sins..." He said to the paralytic, "I tell you, get up, take your mat and go home''' (Mark 2:10-11).

Jesus was opposed to entertaining people by miracles. He refused to perform a miracle to satisfy King Herod's curiosity (Luke 23:8). On other occasions he did not do miracles because of their unbelief (Matthew 13:58), not wishing to 'cast pearls before swine' (Matthew 7:6). The purpose of miracles was apologetic, viz., to confirm his message (cf. Exodus 4:1-9; John 3:2; Hebrews 2:3-4). And this he did in great abundance for 'Jesus of Nazareth was a man accredited by God to you by miracles, wonders and signs, which God did among you through him' (Acts 2:22).

Do not answer a fool according to his folly

It is argued that atheism is folly (Psalms 14:1), and the Bible says we should not answer a fool. We agree with Proverbs 26:4, but we also concur with Proverbs 26:5 which says, 'Answer a fool according to his folly, or he will be wise in his own eyes.' Either the Book of Proverbs was put together by a mad man, or the lesson of the passage is that we have to be careful in how and when we choose to confront false ideas. Don't just argue with someone who will not listen to reason, or you will be just as foolish as he is. But if you are able to show a person the error of his thinking in a way that he can understand, perhaps he will seek God's wisdom rather than relying on his own.

Apologetics is not used in the Bible

If apologetics is biblical, then why don't we see it done in the Bible? By and large the Bible was not written for unbelievers but for believers. Since they already believe in God, Christ, etc., there is no need to prove these truths to them. Apologetics is primarily for those who do not believe, so that they may have a reason to believe.

But apologetics is used in the Bible. Even those familiar with it don't recognize it, since they don't realize that what they are looking at is really apologetics. Moses did apologetics. The first chapter of Genesis clearly confronts the mythical accounts of creation known in his day. His miracles in Egypt were an apologetic that God was speaking through him (Exodus 4:1-9). Elijah did apologetics on Mount Carmel when he proved miraculously that Yahweh, not Baal, is the true God (1 Kings 18). Jesus constantly engaged in apologetics, proving by signs and wonders that he was the Son of God (John 3:2; Acts 2:22). The apostle Paul did apologetics at Lystra when he gave evidence from nature that the supreme God of the universe existed and that idolatry was wrong (Acts 14:6-20).

The classic case of apologetics in the New Testament is Acts 17 where Paul reasoned with the philosophers on Mars Hill. He not only presented evidence from nature that God existed but also from history that Christ was the Son of God. He cited pagan thinkers in support of his arguments. Apologetics was done in the Bible whenever the truth claims of Judaism or Christianity came in conflict with unbelief.

Objections to Apologetics from Outside the Bible

These objections against apologetics arise from assumptions of its irrationality, inadequacy, or fruitlessness. Many come from a rationalistic or sceptical point of view. Others are fideistic.

Logic can't tell us anything about God

This objection is self-defeating. It says that logic doesn't apply to this issue. But the statement itself is a statement claiming logical thinking about God. It appeals to logic because it claims to be true while its opposite is false. That claim, called the law of noncontradiction, is the basis for all logic. A statement that logic doesn't apply to God applies logic to God. Logic is inescapable. You can't deny it with your words unless you affirm it with the very same words. It is undeniable.
Logic in itself can tell us some things about God – at least hypothetically. For instance, if God exists, then it is false that he does not exist. And if God is a Necessary Being, then he cannot not exist. Further, if God is infinite and we are finite, then we are not God. Also, if God is truth, he cannot lie (Hebrews 6:18). For it is contradictory to his nature to lie. Likewise, logic informs us that if God is omnipotent, then he cannot make a stone so heavy that he cannot lift it. For whatever he can make, he can lift.

Logic cannot 'prove' the existence of anything

True, mere logic shows only what is possible or impossible. We know by logic, for example, that square circles are impossible. We know also that something can exist, since no contradiction is involved in claiming something exists. But we cannot prove by mere logic that something actually exists. However, we know that something actually exists in another way. We know it intuitively and undeniably. For I cannot deny my existence unless I exist to deny it. The statement 'I don't exist' is self-defeating, since I have to exist in order to be able to make the statement. So, while mere logic cannot prove the existence of anything, we have undeniable knowledge that something exists. And once we know that something exists (e.g., I do), then logic can help us determine whether it is finite or infinite. And if it is finite, logic can help us determine whether there is also an infinite being.

Reason is useless in religious matters

Fideism argues that reason is of no use in matters that deal with God. One must simply believe. Faith, not reason, is what God requires (Hebrews 11:6). But even in Scripture God calls on us to use reason (Isaiah 1:18; Matthew 22:36-37; 1 Peter 3:15). God is a rational being, and he created us to be rational beings. God would not insult the reason he gave us by asking us to ignore it in such important matters as our beliefs about him.

Fideism is self-defeating. Either it has a reason that we should not reason about God or it does not. If it does, then it uses reason to say we should not use reason. If fideism has no reason for not using reason, then it is without reason for its position, in which case there is no reason why one should accept fideism.

To claim reason is just optional for a fideist will not suffice. For either the fideist offers some criteria for when to be reasonable and when not, or else this timing is simply arbitrary. If a fideist offers rational criteria for when we should be rational, then he does have a rational basis for his view, in which case he is not really a fideist after all.

Reason is not the kind of thing in which a rational creature can choose not to participate. By virtue of being rational by nature one must be part of rational discourse. And rational discourse demands that one follow the laws of reason. One such principle is that one should have a sufficient reason for his beliefs. But if one must have a sufficient reason, then fideism is wrong, since it claims that one need not have a sufficient reason for what he believes.

You can't prove God by reason

According to this objection, the existence of God cannot be proven by human reason. The answer depends on what is meant by 'prove.' If 'prove' means to demonstrate with mathematical certainty, then most theists would agree that God's existence cannot be proven. This is because mathematical certainty deals only with the abstract, and the existence of God (or anything else) is a matter of the concrete. Further, mathematical certainty is based on axioms or postulates that must be assumed in order to get a necessary conclusion. But if God's existence must be assumed to be proven, then the conclusion that God exists is only based on the assumption that he exists, in which case it is not really a proof at all.

Another way to make the point is to note that mathematical certainty is deductive in nature. It argues from given premises. But one cannot validly conclude what is not already implied in the premise(s). In this case one would have to assume God exists in the premise in order to validly infer this in the conclusion. But this begs the question.

Likewise, if by 'prove' one means to reach a logically necessary conclusion, then God's existence cannot be proven either, unless the Ontological Argument is valid. But most thinkers hold that it is not. The reason one cannot prove God by logical necessity is that formal logic, like mathematics, deals with the abstract. Unless one begins with something that exists, he can never get out of the purely theoretical realm. If there is a triangle, we can know logically and with absolute certainty that it must have three sides and three corners. But there may not be any triangles in existence anywhere except in someone's mind. Likewise, unless we know something exists, then logic cannot help us to know whether God exists. And logic by itself cannot tell us whether anything exists.

If by 'prove,' however, we mean 'give adequate evidence for' or 'provide good reasons for,' then it would seem to follow that one can prove the existence of God and the truth of Christianity.

No one is converted through apologetics

The charge is made that no one ever comes to Christ through apologetics. If this implies that the Holy Spirit never uses apologetic evidence to bring people to Christ, this is clearly false. C.S. Lewis noted that 'nearly everyone I know who has embraced Christianity in adult life has been influenced by what seemed to him to be at least a probable argument for Theism'. Lewis is an example of an atheist who came to Christ under the influence of apologetics. The sceptic Frank Morrison was converted while attempting to write a book refuting the evidence for the resurrection of Christ. Augustine tells in his confessions how he was led toward Christianity by hearing a Christian debate an unbeliever. Harvard Law School professor Simon Greenleaf was led to accept the authenticity of the Gospels by applying the rules of legal evidence to the New Testament. God has used evidence and reason in some way to reach virtually all adults who come to Christ.


R.L. Bush, ed., Classical Readings in Christian Apologetics A.D. 100-1800
D. Clark, Dialogical Apologetics
G.H. Clark, Religion, Reason and Revelation
W. Corduan, Reasonable Faith: Basic Christian Apologetics
N.L. Geisler and R. Brooks, When Skeptics Ask: A Handbook on Christian Evidences
P. Kreeft, et al, Handbook of Christian Apologetics
G.R. Lewis, Testing Christianity's Truth Claims
C.S. Lewis, God in the Dock
J. McDowell, Answering Tough Questions Skeptics Ask, Evidence That Demands a Verdict
J.W. Montgomery, Faith Founded on Fact
J.P. Moreland, Scaling the Secular City: A Defense of Christianity
F. Morrison, Who Moved the Stone?
W.M. Smith, Therefore Stand

This is an excerpt from 'The Baker Encyclopedia of Christian Apologetics' by Norman L. Geisler available in the UK from STL through Wesley Owen bookshops.

Used by permission of Baker and Baker Academic division of Baker Publishing Group, copyright © 2007.
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