Adrian, I think one would have to define "God" in specific terms in order to determine if "God" exists or not. Is God simply the "prime mover" that started the universe? Does this God still exist? Does God think? If so, with what? etc. etc. If you give god certain human qualities, such as thinking, then you can rule out its existance...to a high degre of certainity.
"On Earth as it is in Heaven, the Cosmic Roots of the Bible" available on the Amazon.