Let me ask you this.

The fact that God exists is a no brainer. How else would we be here? [1]

But there are many different books out there that, to some dude or an other, are all the word of God.

How did you come accross your book of choice and what makes it the best choice of them? And it would be grand if you compared your choice to the choice of using our mind and our conscience instead of a book to lead us through God's Creation, marveling all the while.

[1] I'm serious about this. But I should probably clarify that I'm refering to God in the Spinozian sense:

Known as both the "Greatest Jew" and the "Greatest Atheist", Spinoza contended that "God" and "Nature" were two names for the same reality, namely the single substance (meaning "to stand beneath" rather than "matter") that underlies the universe and of which all lesser "entities" are actually modes or modifications.