In 1900, no historians thought Jesus was like Moses, Abraham, and Adam, made up from whole cloth. In 2000, some did. Today, more.
The scenario as I understand it is that Paul's writing came first. But to get a congregation to pay attention they found they had to invent a corporeal Jesus to have said their things, then apostles to have heard them, then a bio for where and when, and finally gospels to tell it in.
For those who object that such a thing wasn't done, consider Moses and, really, all of Genesis and Exodus. Iliad. Thor'n'Loki. It was not just done, but positively demanded.
