Many a good atheist have experienced the futility of presenting logic and reasoning to a devout theist. As I have just completed P. Boyer's Religion Explained -The Evolutionary Origins of Religious Thought my viewpoint of religion and the theistic mind has been changed dramatically. Why?
My new understanding of the theistic mind from a cognitive perspective has forced me to realize that tools such as science and logic and even religious scriptures are not that important to the average supernatural believer. This is true across all religious peoples from the jungles of Africa to the mountains of India. The notions of "gods and ancestors" is of a practical concern to most religious people. A believer's mental representations of supernatural agents are not concerned primarily with their general properties or powers but rather about specific instances of interaction with them. This is a crucial point according to Boyer. General interpretations of the supernatural are a small part of the many representations activated in people's minds. Quoting Boyer- "The religious furniture of the mind is cluttered with far more specific representations such as "God is punishing so-and-so and that's why he is ill," "Such and such ancestor was not pleased with our sacrificed pig," etc."
In light of this practical aspect of religion it is now not surprising that so many of the world's religious turn a blind eye to the specifics of the nature of god(s) and ancestors. They are not interested or concerned in the minutia of how a god or ancestor exists or is even invisible. As a result most are indifferent to logic and reasoning as applied to religion, that which an atheist considers so vital to understanding the world we live in. To an atheist the issue of cognitive dissonance should surface in the mind of the believer when presented with compelling arguments. But somehow the practical application of religion overrides this potential compulsion.
You can lead that horse to water but you can't make her drink.