Calling it fairy tales is never, ever going to get that side of the argument to converse in any manner better than defense. Engagement would be better. Some very, very smart people believe exactly the way you wish they wouldn't.
Unfortunately, basing your worldview on unprovable and self-referential axioms like "the Bible is the word of God because it says in it that it is the word of God" and "the Bible is literal truth because it's the word of God" makes it hard for people who base their worldview on scientifically derived axioms to debate with you effectively. If you can't agree on the foundational axioms, then debate on higher order results of those is usually pointless. I think that's the crux of the impasse there. I'm not sure if I've ever seen someone change their fundamental beliefs, probably because it would involve refactoring everything, and that's a ton of work.
