You were claiming John couldn't have been written by John because it was written in AD100. I did the maths and shown how it definitely could have been written in AD100

I'm not making a claim, I am rebutting one. I am merely stating there is no evidence to support that John the apostle actually wrote John. There are inferences that lead people to believe that John wrote it, but again, these are oral traditions and are prone to embellishment or errors over time.

The second quote doesn't even contradict anything I said. Just because stories were exchanged orally first, doesn't mean the written accounts are firsthand.

Lol, it contradicts the claims you made about the first quote? It's silly how often your position changes.

The main reason people say it is a forgery because Josephus was a practicing Jew and a Jew wouldn't say that (circular reasoning)

That's not circulatory reasoning..... That's just reasoning. Why would a Jew believe in the resurrection of Christ? Plus, the reason historians almost unanimously agree it's been edited is because how out of place the claims and passages about Jesus are in the original text. We also know that the translators we receive the text from are not reliable narrators.

Is it possible for a non Christian to write something in defence of Christianity, or not?

In defense of Christianity......yes, but they wouldn't believe in the holy resurrection of Christ, as that would make them a Christian.

If it isn't, then you cannot dismiss the new testament and Church Fathers, lest you be irrational

That's a false dichotomy...... Even though I and most historian believe it to be a forgery, if I didn't I could still make a claim that Jesus was simply a historical figure and that there still is no evidence miracles or evidence that's supports him as a diety.

There are plenty of historical records we utilize as important works of history, but understand the authors may not be reliable narrators. Naram-Sin declared himself a diety, and these claims are backed by other contemporary sources... We use these sources to validate his existence as a historical figure, but does that also mean he was really a diety?

I don't really think you understand rationality, you are only using a narrow scope of logic instead of the broader understanding of rationality. Pure logic can lead to logical fallacies like your uses of false dicotomy and circular reasoning.