With most religious people, their faith is founded upon and subsequently set up to support their feelings. It's hard to use facts to fight fellings that were not acquired by any logical means beyond a feeling that prompts religious proponents to "know in their hearts." One thing the Bible got right in my opinion is that the heart is deceitul above all things. As human beings we constantly both consciously and subconsciously spend time rationalizing our feelings and perspectives to justify our outlooks and behaviors.
I am willing to bet that religion would all but disappear if it were truly deity-centric as opposed to being human ego-centric. We create gods to in effect deify ourselves and give value to our norms, mores, ideals, and perspectives. Our gods tend to know and care for us individually giving the individual a sense of being special and intrically connected to a grand plan designed by the master of the universe. Gods are almost always advertised as beings that will bless those who adhere to certain rules and buy into certain outlooks. If the notions of being known, blessed, predestined, and favored by a powerful deity were removed, I doubt there would be many religious practicioners.