The parent said "depending on which you subscribe to." There are millions of people who believe the phrase you quoted. So it is a counter argument, regardless of its objective true-ness.
Exactly. If we were discussing Harry Potter lore I would treat those books the same way. I honestly don't see any meaningful distinction between religions and fandoms of other creative works (except maybe that fewer people have been killed in the name of Harry Potter).
That said, I was really just making a witty remark. I have no reason to treat biblical accounts as factual (especially given the long and complex history of why biblical canon is what it is and the unreliability of narrators with questionable identities who weren't even alive at the time of the events they're describing).
The direct speech of Jesus in the bible is not necessary the literal word of Jesus of Nazareth the (possible) historical person, but under various interpretations of Christianity it is the literal word of Jesus Christ, the (fictional) character in the biblical narrative. The only difference is that Christians generally seem to think the biblical character is an exact description of the historical person -- for which there doesn't seem to be any reliable basis.
That's not really a counter argument, as what qualifies as "biblical account" was decided many hundred years after the historical events.