snowbird - "When Jesus of Nazareth spoke of the Flood, He also mentioned Sodom and Gomorrah. Was that a parable?"
Maybe. Maybe not. Surveyers have found what appear to be ruins at the bottom of the Dead Sea, but that's not the point.
The point is that a parable arguably has just as much value as a teaching aid than an actual historical account, and Jesus of Nazereth was, first and foremost, a teacher. The tendency for some "Bible-believing" Christians to assume that the Genesis-as-literal-history concept is the only valid one is, in reality, a relatively recent phenomenon.
While researching The Case for God, historian Karen Armstrong discovered that Biblical literalism was a sort of (ironic) byproduct of - believe it or not - the Enlightenment; the rational/scientific method for explaining the world around us had had unparalleled success, but an unexpected side effect was the discrediting of mythology, to the point where the word “myth” even became, for all intents and purposes, associated with “lie”. In reality, the two terms originally had different connotations.
I light of that, how could people who revered the Bible associate their cherished scriptures with lies? They couldn’t, of course, and so Young-Earth literalism, well, evolved into its the modern-day (and occasionally militant) form.