I agree with what you're implying, that most of the people in BC were pretty ignorant.
Do you honestly think the people of that epoch could grasp metaphors or understand an allegory? How high do you suppose their literacy rate was? When most of your audience has the IQ of a sandal, I thinks it's safe to say they will interpret everything quite literally. I refer to an audience since any copies of the Bible would have been rare commodities, hence the spoken word would be the primary source of information. Face it, they were primarily idiots...
That's why I do believe that the bible is inspired by the hand of God.
What other explanation is there?
Aliens. Ya, that's it, aliens.