How do you deal with a religious family?

[Aractus]

You haven't produced any evidence that any of the NT authors deliberately lied. You haven't even provided evidence of why they would do so.

Proving actual intent is irrelevant. You've provided evidence against their credibility and their is a a clear motive.

Your argument makes no sense. There's general agreement that the authors of Matthew and Luke used a common written source (or sources) along with proto-Mark when making their Gospels. I can show you Greek that is letter-for-letter identical, thus has to be from a common written source (or of course one is directly copied from the other). People that "make stuff up" don't meticulously copy down records from another source.

The next most important author is of course Paul who wrote at least 8 or 9 of the NT books, and may have written 13-14. Firstly, if he was lying he would start to contradict himself. Secondly - why would he lie? He is maryterd for his faith according to early 2nd century church fathers and consistent with his reports of imprisonment. So there's no benefit in it for him to be a liar.

But you don't know if they are telling the truth. In fact, that is precisely the question on the table - are those writers telling the truth?

That's a stupid question unless you have evidence. You may as well claim that all the ancient Egyptians were liars and their writings tell us nothing about their culture.