But the Gospels, and the other Christian writings of the times, don't have to offer evidence, they are evidence. Evidence of the existence of a historical Jesus. Unless that is you can demonstrate that all these different writers were in fact engaged in a collusive conspiracy to convince people that such a person existed when he never did. Surely an unlikely proposition, and it seems much more sensible to take it that there was such a person, they believed the most important who ever lived, and to themselves they were chronicling and recording, not inventing.
Evidence is what is used to prove the truth of an assertion. A assertion is true when it is proven by evidence. The Gospel writers
assert that Jesus was born of a virgin, preached, was crucified, died, and was resurrected. This assertion must be
proven using
evidence. What evidence is provided to prove their assertion? To argue that Jesus must have existed because Christians believe he exists is not evidence.
You seem to give Gospel truth the exact opposite to the customary meaning; if it's in the Gospels, it can't be true. I'm afraid that if you want to discredit a large body of near-contemporary writings by many different hands as deliberate invention and no evidence of anything whatsoever, you have to make more of a case for that than just calling it all propaganda. And actually apart from John, universally agreed to be the last-written of the canonical four and which has the clear intent of persuading Christians to a particular philosophical view of Christianity, the Gospels don't have the feel of propaganda. They just seem like narrative. Sometimes confused and disordered narrative too, unlike John's smooth flow, the roughness again adding to the authenticity.
No. My position is that if it's in the Gospels it must be proven using evidence. That one person or a hundred wrote the Gospels is evidence of nothing. The burden of proof is on the person making the assertion.
As for corroboration, Matthew, Mark and Luke aren't Tweedledum, Tweedledee and Tweedlethree even if we discount John, which despite what I've said I don't entirely. And then there are the various epistolary authors, the non-canonical material and the writings of the earliest Church Fathers. I'm not sure how much corroboration you think would be enough. Yes they are all Christians, but clearly they are independent and separate people. The demand for non-Christians of the time to have left accounts of what was no doubt assumed to be yet another of the myriad cults and would soon enough be vanished and gone is not altogether sensible. I don't suppose many people who weren't or did not become Christians would have been in the least interested.
None of the Gospels, with the
possible exception of Mark, were written by eyewitnesses. The Gospel of Luke states this explicitly: "Since many have undertaken to set down an orderly account of the events that have been fulfilled among us,
just as they were handed on to us by those who from the beginning were eyewitnesses and servants of the word, I too decided, after investigating everything carefully from the very first, to write an orderly account for you, most excellent Theophilus, so that you may know the truth concerning the things about which you have been instructed." The Gospels were written based on oral traditions, not by the actual eyewitnesses to these events. In any event, mere testimony without independent corroboration is not evidence.
I don't think we know too much about the Roman Empire that is not from Roman sources. Did that not exist, then? Remember, I am not asking you to accept that Jesus was born of a virgin, performed miracles and rose from the dead. I don't believe that myself. All I am challenging is your original assertion that there is no historical evidence for the existence of the man Jesus. There is plenty, unless you arbitrarily dismiss it all as invention. Which, as I have tried to show, is not a reasonable approach to the question.
I'm repeating myself here. Christian sources are liable to the same burden of proof as any other source. You're not asking me to believe that Jesus was the Messiah, but the Gospels certainly are, and that's the problem with accepting their assertions as evidence of anything without proof. What evidence do you have to prove the Gospels' assertion that Jesus was a historical person?
To your last point, was Julius Caesar a Christian? By his own account his actions in Gaul were akin to what we would consider genocide. By most reckonings, the greatest mass murderer in history was not Hitler, Stalin or Mao but Genghis Khan, who I doubt ever heard of Christianity before his campaign of slaughter began. I could adduce countless other examples. Wickedness and intolerance are not uniquely Christian faults, and if people hadn't been killing others in the name of Christianity it would have been in the name of something else. The artistic, cultural, moral and spiritual legacy of Christianity may be stained by by the things done in the name of Christ, but is not altogether devalued.
When did I ever assert that Christians had a monopoly on genocide or wickedness or cruelty? This is a straw man.