I recently read G.A. Wells's book "The Historical Evidence for Jesus", which was written back in the early 80s. Considering some of the books I have read in the past few years, this was basically 'more of the same' with a few interesting nuances and insights along the way.
Wells believes that there was no historical person at the origin of the Jesus stories. Rather he, along with a number of other 'mythicists' hold that the gospel stories are myths made into history, rather than history wrapped in legends.
The book is exhaustive and goes into all the relevant 1st and 2nd century writings, as well as going completely off at a tangent and asking questions about the Turin Shroud. But when its on track, the book is interesting, even if much of this has been said in other ways many times since then (and a few before).
Wells sets out a timeline of the early writings, beginning with the letters of Paul, then going through some of the later epistles, including some non-canonical ones, the gospels, the church fathers, and so on.
The strongest part of his argument is in the parts he talks about Paul. It is quite clear from this analysis that Paul (or whoever wrote the 'authentic' Pauline epistles) says very little about any historical Jesus. The highlights of this are those passages where Paul is writing to whichever church and issuing advice for right living, etc. Sometimes, indeed most of the time, he does not claim these instructions come from Jesus, and there are several instances of things Paul is trying to convince his readers of where it would have been very useful if he could have quoted Jesus, but doesn't. But funnily enough, in the gospels, Jesus addresses those issues in clear and unambiguous ways. Wells's case is that if Paul knew of these sayings, he would have used them. He doesn't use them, so he didn't know them. Which suggests either that there was a lot about Jesus that Paul simply didn't know, or that those stories about Jesus were not in circulation at the time of Paul, perhaps because those stories about Jesus had not been devised yet.
In this I am convinced, it is clear that Paul had no knowledge of some of the gospel stories. Does that mean there was no historical Jesus? No it does not. It only means that Paul did not know the stories and, assuming he had interactions with Peter and James, as claimed in the epistles, it suggests that they did not know or did not pass on those stories.
So I am convinced that the gospel stories grew and developed after the time of Paul, and that Paul does not know or care much about a historical Jesus. I remain to be convinced that there was no Jesus.