On the contrary, God states in Genesis 7:4
...for after other seven days I am sending rain on the earth forty days and forty nights, and have wiped away all the substance that I have made from off the face of the ground.
God specifically states that he is sending the rain. This is not just an unusual meteorological phenomenon, this is directly caused by a deity. That, I think, qualifies it for the 'supernatural' moniker.
The point is that rain is not an unusual meteorological phenomenon at all. It is a perfectly ordinary, natural phenomenon. God sending rain is, biblically speaking, an ordinary natural event. All rain is sent by God, so God sending the rain for the flood is not a miraculous event. It is God acting through nature in an ordinary way.
The Bible does not say the Flood occurred in the complete absence of divine intervention.
Nor am I suggesting that. But "divine intervention" does not necessarily imply unnatural means.
Thus, since exegesis has failed us, extra-Biblical knowledge can be employed to see how the Flood could have occurred. However, since it turns out that a purely natural (i.e., no "goddidit"s) explanation cannot account for the data, one must begin positing "goddidit"s to keep the story within the realms of possibility.
Ah, well now you are getting into the question of how to deal with the text in the light of extra-biblical information. However, no matter what the extra-biblical information says, we still have a text that suggests a flood due to natural (albeit divinely directed) causes. There is nothing in the text to suggest miracles that go against the order of nature.
In short, either one requires a supernatural explanation for what could not have occurred naturally, or one rejects the relevant texts as not literally true (or simply not true at all).
Please, please, please do not categorize a non-literal understanding of the text as a rejection. It would only be a rejection if the literal meaning was the only legitimate meaning.
Upvote
0