Don’t teach it as anything to fucking fifth graders though. That is just not appropriate at that reading level.
But apparently it is in Oklahoma now.
I would say nearing the end of high school at the earliest if you want to be able to teach the Bible as literature. It might even not be grade school appropriate at all and should just be taught on the college level.
After all, unless you’re teaching it dishonestly, you’ll want to cover translation issues, which would require a lot of reading and analysis.