Identifying the word of god

[robvalue]

I have a question for the religious. In simple terms, how can you spot the difference between a text that is the word of god, and one that just says it is but was written by men?

To paint a picture and to produce a non-biased answer:

Imagine you have all your current knowledge and experience about any and all holy books wiped from your mind.

Then you are presented with two books. The names aren't important, let's just call them A and B. It has been guaranteed to you somehow that one of these really is the dictated word of god. The other is an elaborate fake, a book written by men to mimic the style of the true book.

Both books contain their accounts of what god is, what its laws are, various stories, and proclaim that they are the one and only true word of god. They both seem about as convincing as each other after a read through.

My question is, how do you decide which one is actually the word of god, and which one is the fake? What is your criteria?