text: We might have no evidence for the God of Moses (a.k.a "Adonai", "Allah" or simply "God" to the Christians), but just because we don't doesn't mean they don't exist. Similarly, we may have believed the existence of yet-to-be-discovered elements, but we didn't have evidence of its existence until these elements found its way into the periodic table. That's why we got to study these objectively.
  
  Now, about previous discussions, it's true that the Bible's books aren't written in what should be Jesus Christ's time BUT the Bible is not "one source". The Bible are many books in one, with different writers writing in different times, so we need to validate these now: somehow. And again, we wouldn't know of the existence of some elements now if not for someone who believed and sought it.