The claim made by believers is that the bible is a message from an omnipotent god who wants everyone to act on it. (Some believers claim it is a "personal" message; but I will not address that at this time.) An omnipotent being thinks it is important that I know a message comes from him and he uses a two-thousand-year-old text of dubious authorship? Can't he tell me directly?
Consider. If you are trying to get an important message to someone, and all options are available, what method do you use?
A> Tell him directly.
B> Call him on the phone.
C> Send him a letter.
D> Leave an anonymous note on his doorstep.
E> Have a homeless person give him the message.
The nature of the bible reeks of inauthenticity. There may be a supernatural being behind it. But he is not who he says he is.