If the historical Jesus was an "average itinerant preacher" then he isn't the Biblical Jesus in any meaningful sense.
If there was a real guy called Jesus of Nazareth around the early 1st century, who was crucified during Pontius Pilate, and his disciples and followers that formed the core of the religious movement later called Christianity, to argue that Jesus was nonetheless "completely fictional" becomes a mere twisting of words that miscommunicates its intent.
At this point no matter how much evidence appear for a historical Jesus, you can argue that he's fictional because he doesn't match well enough the story of the Bible. Well, yeah, ofcourse he won't match up well enough the story of the Bible, because the story of the bible is filled with lies and embellishments. But at the bottomline either one or more people sat down and thought "We'll make up a character called Jesus of Nazareth, and have him preach to people and get executed by crucifixion by the Romans", or there was a real Jesus of Nazareth who preached to people and got executed by crucifixion by the Romans.
As for the comparison with Batman, Robin Hood and so forth it seems to me that your division of story elements into "meaningful"/"core"/"crucial" and not-meaningful/core/crucial is post hoc. | Well they're not.
To the Christians of, say, 80AD it might well have been that Jesus being crucified and being from Nazareth were just as much a part of his story as murdered parents and a bat suit are to Batman.
I'm getting tired, and this is becoming ludicrous. You're not telling me why these things were important, if they weren't real. Why would someone create such horrible ill-fitting to prophecy elements as the name "Jesus" and the location "Nazareth", when it was the name "Emmanuel" and the location "Bethlehem" that were the significant ones? What is the meaning of the crucifixion? Christian still don't agree on this, only saying that it is for some reason part of the divine plan, but they don't have a reason on why.
Why? Why? Why? If you can't answer that, then the simplest explanation is that the name "Jesus of Nazareth" and the crucifixion were not elements that were authored, they were elements they were stuck with, because they were real
I think a lot of Christians uncritically
I'm not a Christian, I'm an atheist. That doesn't mean I have to ignore what the evidence tells me.
And Jesus of Nazareth was a historical figure. So was Mohammed. And Socrates too. That's what the evidence tell us.
Why would someone create such horrible ill-fitting to prophecy elements as the name "Jesus" and the location "Nazareth", when it was the name "Emmanuel" and the location "Bethlehem" that were the significant ones?
Maybe it's down to all the fantasy stories I've read, where prophesies are almost always fulfilled in an unintuitive way (although the Greek oracles were like this too,) but I've always found the theological explanation for Jesus's name entirely satisfying. Emmanuel means "God With Us," and if J...
To break up the awkward silence at the start of a recent Overcoming Bias meetup, I asked everyone present to tell their rationalist origin story - a key event or fact that played a role in their first beginning to aspire to rationality. This worked surprisingly well (and I would recommend it for future meetups).
I think I've already told enough of my own origin story on Overcoming Bias: how I was digging in my parents' yard as a kid and found a tarnished silver amulet inscribed with Bayes's Theorem, and how I wore it to bed that night and dreamed of a woman in white, holding an ancient leather-bound book called Judgment Under Uncertainty: Heuristics and Biases (eds. D. Kahneman, P. Slovic, and A. Tversky, 1982)... but there's no need to go into that again.
So, seriously... how did you originally go down that road?
Added: For some odd reason, many of the commenters here seem to have had a single experience in common - namely, at some point, encountering Overcoming Bias... But I'm especially interested in what it takes to get the transition started - crossing the first divide. This would be very valuable knowledge if it can be generalized. If that did happen at OB, please try to specify what was the crucial "Aha!" insight (down to the specific post if possible).