Clearly the Jesus we encounter in the Bible is a mythological persona. That one isn't real. But there are clues to suggest that he--or whoever the Jesus god-man character was based on--really did exist. The best evidence for this is the seeming conspiracy by Biblical authors to place his birth in the City of David. The two authors who write of his birth story give wildly conflicting reports of the nativity. Luke goes so far as to invent a Roman census for the purpose of moving Joseph and Mary from their home in Galilee to Bethlehem for Jesus' birth.
If Jesus were a wholecloth fabrication, why not just have him from Bethlehem? Why the subterfuge? To me, the fact that the authors strain to place his birth in the only place where the prophecy could be fulfilled indicates that there was a particularly influential rabbi from Galilee around that time.
I do cringe at the idea of people calling him a great moralist. He was the leader of a death cult, and his teachings reflected that. Turning the other cheek, giving no care for the morrow, abandoning your family; these injunctions are irresponsible when viewed in any other context than "The world is about to end." We use some of his words as platitudinous ideals, but even the most basic of them don't really pass the test when scrutinized. For example, is it even possible to love your neighbor as you love yourself? How could a society survive without human judgment? Our society relies on being able to judge people based on their motives and actions. And how moral is it to allow your enemy to strike you? That's immoral on any level, from the kid allowing himself to be bullied, to the nation who allows invaders to cross its borders unimpeded. The end result for both is destruction. This can only be considered moral if you believe the world is about to end and Jesus is God incarnate. Otherwise, he's just a guy leading you down a primrose path.
Anyway, that's my take.