To clarify, I do not say that the earliest Jesus-Christians falsified his existence for some nefarious purpose. Rather, I say that they constructed Jesus as a focus for myths, and never expected to be taken at face value. As Clement and Origen said, literal belief in a historical Jesus is a religion for children.
I think some mistake the weight of seventeen hundred years of assumptions for historical evidence. Josephus bears the only non-Christian testimony of Jesus' existence, and as detailed in my last post, this document runs sharply against Josephus' beliefs and inclinations, and is most likely a forgery from two or three centuries later.
It is not, as I already hear some of you shouting, implausible that the earliest Christians fabricated a live focus for their myths and their mystery faith (one of many very very similar faiths). Think-- the Christians were organised and energetic. They were one of many groups proclaiming the message of a salvatory god-man. In a time when hardly anyone travelled and mass communications did not exist, nobody would really be in a position to stand up and declaim the Gospel as ahistorical. Even if someone was, they had no means of communicating this and no weight behind their voice. An alternate explanation could be that the people at the time likewise understood the Gospels to be myth and allegory, and thus nobody saw any point in denouncing them as falsehood. Once the stories gained momentum, a decision to treat them literally would (and, in my opinion, did) have staggering effects upon all future interpretations of the texts.