C.S. Lewis, who was a literary scholar long before he was a Christian, makes the scholarly point that the Gospel accounts read nothing like legend or myth. Some critics compare them to historical fiction, but Lewis also points out that that is a fairly modern genre of literature that was unknown until about 400 years ago. Lewis wrote:
I have been reading poems, romances, vision literature, legends, and myths all my life. I know what they are like. I know none of them are like this. Of this text, there are only two possible views. either this is reportage...or else, someone unknown writer...without known predecessors or successors, suddenly anticipated the whole technique of modern novelistic, realistic narrative...The reader who doesn't see this has simply not learned how to read.
Claiming the Gospels are myth has become popular among atheists recently, but there's a very good reason why experts have never treated the Bible as myth or historical fiction. Literary scholars know the difference between myth and eyewitness accounts. Whether they believe them is different matter. They recognize the characteristics and note the differences.
Timothy Keller makes a number of other observations that count toward the Bible's early historicity. (from Gospel Christianity 1.0 Participants Guide)
- Legends are written down long after events they allegedly recount; Mark and Luke wrote just 30-40 years after Jesus' death. All of the Gospels were written in the lifetimes of those who witnessed Jesus.
- Jesus' miracles couldn't have been invented in early accounts. Events like Jesus feeding thousands would have been contradicted by eyewitnesses still living.
- The Gospels include counter-productive details that wouldn't have been made up if the goal was to promote their message. Jesus expresses a desire to avoid the cross, cries out that God has forsaken Him.
- The literary form is detailed in a way legend is not. For example, John 21 mentions 153 fish caught.
Greg takes a close look at the claims that the Gospel mimic other deity myths. The claim just doesn't hold up to fact.