Nothing like being over a year late to the party, but I spotted this thread while searching for another.
It seems in my observation that many people, theists and atheists alike, but especially theists, simply assume there is a ton of "archaeological evidence" out there when there really isn't. One of my favorites is the referencing of Jesus (as in biblical Jesus) as a real, flesh-and-blood person (or Muhammad, or Buddha). I've been trolled to death on this very site for daring to suggest that with no eye-witness accounts, earliest accounts being agenda-laden religious texts, and earliest secular accounts being conspicuously few and full of contextual/credibility red flags, that bible Jesus could plausibly be (looks around for my personal trolls) *gasp* mythical? That at best, if any of the bible descriptions do happen to describe a real person, we have no way to tell that from the bible descriptions that are purely the author's artistic license.
I think that's where the real flaw in logic occurs. As it's a common name, we can infer that even if every word of the bible was purely pulled out of Paul's ass, he got the name from somewhere. Just like Frank Baum got the name "Dorothy" in the Wizard of Oz from somewhere. But is inspiration-behind-the-character-Dorothy and character-in-the-book-Dorothy one in the same?
The same goes for places. Say we prove there really were twin cities called Sodom and Gomorrah. Awesome, but that doesn't prove anything about the biblical story other than they used a real name-place. I'm currently reading a vampire book set in St. Louis Missouri. The existence of St. Louis doesn't make the book a true story.
However, someone will take that smattering of evidence, such as "city X was a real place" or "Tacitus acknowledged that there is a religious cult called Christians whose god-man is named Jesus" and take that to mean any story set in that city must be true, or inspiration-behind-the-name-Jesus is preserved faithfully in canon biblical text. It/he could be, but the archaeological evidence is far from proving it scientifically or historically.
Meanwhile, a couple thousand years of simply assuming it's true and it's amazing how many people simply never think to question it. As a geology professor recently said to me, "Common wisdom is a powerful tool. But every great scientific breakthrough started out as a crackpot idea questioning common wisdom."
All that said, just ask the theist to produce the evidence. Few can. They're just parroting the "common wisdom" parroted to them by the church.