The witnesses are the evidence.
1. Eyewitness testimony is unreliable
2. Eyewitness testimony delivered decades after the fact is even more unreliable
3. Allegations of eyewitness testimony from vested interests who weren't there themselves is highly questionable.
You have no proof it never happened and the witnesses never saw it.
And you have no proof Mohammed didn't ascend on a winged horse, that Joseph Smith didn't have an angel help him decipher conveniently disappearing golden tablets, that Nut and Geb didn't give birth to the world and that Xenu didn't blow up DC-9 shaped nuclear bombs to embed tortured thetan spirits into the Earth, yet you don't (I suspect) accept any of those claims.
The burden of proof is on the claimant - we aren't saying, definitively, 'that never happened', we're just saying that your claims are not believable, and you don't have any evidence to put before us that would make us put them in a different category to, say, the King Arthur myth.
We deal with the bible the same as anything from history. It is all presented from people at the time. You can decide what you believe but you cannot disbelieve one thing by choosing without disbelieving the other... but there is selective reasoning so you choose what you believe.
We do deal with it the same as with anything from history - which is to say that we update the ideas with later ones as they become evident, and we don't make assumptions that can't be supported by the available data.
History is replete with evidence of Christianity, and there is some evidence for a figure around whom the story of Jesus is founded. There's nothing to back up the idea of a god or his magical avatar, however.
O.