This thread is an interesting and exhaustive (exhausting?) read that fails to bridge the strongly held differences of opinion on the subject.
The doubters are looking for some hard physical evidence of his time on earth, a copy of the Roman order to crucify Christ, a piece of Jesus’ personal property, a contemporary document of some kind that specifically references Jesus in some way, like maybe his Carpenters’ Union membership card. The problem with that is that in his time he lived his life like a civilian, he was just another guy in sandals. Why would Jesus of Nazareth have warranted specific record keeping any more so than Albert Wilson of Jerusalem?
On the other side of the chasm are centuries of study that evaluate what boils down to anecdotes handed down by believers and eventually written, as well as analysis of what is known of the socio-political climate of the time. From this they draw conclusions as to the accuracy of the record reflected in the Bible and related scripture. It’s detailed historical sleuth work that aims at statistically confirming hypothesis in the face of a lack of first hand data.
In the end you have two groups setting a very different standard for establishing the truth, which leaves us with one deciding variable, faith. Either you have it or you don’t. The rest is just a lot of wind.