Your friend saw this resource on bethinking.org and thought you should see it:
How Big Are the Differences in the Gospel Documents?
How big are the differences between the hand-written copies of the Gospels' accounts of Jesus? Do these undermine what we can know about him?
See the full resource online by visiting bethinking.org:
is a collection of resources which aims to make sense of the big questions of life about God, Jesus and Christianity.