The Noah's myth is enough to demonstrate my point of view. It already existed in most other religions (summerian, phenician...) and it is a transformation of something that really happened, the black sea that filled up 10 or 12,000 years ago.
Like the myth of the arch of noah, all the rest of the bible (same for the koran) is just a compilation of an old oral tradition whose roots are real events, totally transformed and gradually losing all its meaning as time went on. It's just a compilation of very old moral principles. Interesting on a historical point of view, but nothing "holy".