It's all about whose textual criticism you believe. You can find people who argue one way. The Old Testament professors I studied under would argue a different way. Just one example: https://genesisapologetics.com/faqs/gilgamesh-epic-which-cam...

There are other things in the Bible that challenge me more than textual criticism.

On the flip side, I'd say the core "rationalization" I have for my belief is what the Bible teaches about sin. It's obvious to me something is very wrong with with the world we live in. I think the Bible explains convincingly both what's wrong and what the fix is.