I'm not convinced that a book that is absolutely true in every detail needs to have embedded warnings: believe every word of this or burn forever. I don't think a book that has been proofread and certified error free by the creator of the universe would contain the kind of context switches found in the Bible. Slavery is OK for some times and places, genocide is OK for a startup nation, incest is OK when the creator has killed off all the eligible non-relatives, certain foods are unclean for a while (possibly for health reasons, but then why give the OK 1900 years before the health reasons are understood?), divorce is OK, then not OK (maybe it was never OK, but permitted for a while because people really, really wanted to get divorced, so it was allowed).
All these suggest an evolving code of ethics and morality. At the very least they suggest an evolving understanding of morality.