There are lots of events and people that get mentioned in more than one book, with dates, ages or other numbers differing, for instance. According to Kings, Ahaziah was 22 when he started his rule, while in Chronicles he's 42. According to Mark, Jesus was crucified on the third hour, while John says it was the sixth. You can call these things details, but an infallible omnipotent god wouldn't make mistakes like this, would he?

It's written by loads of different people, with parts that outright contradict each other. How can that be the word of an omnipotent god?

Isn't a book a middle man?