People were being eaten by lions rather than simply renouncing Jesus in the decades following His crucifixion. That being so close to the "genesis" of the story lends some serious credibility to the simple matter of His existence.

Mind you, it only took a couple hundred years for THE Roman Emporer to declare Christianity the religion of Rome. That would be comparable to George Washington being fabricated, and the American Independence occuring by coincidental happenstance. As in, not very likely.