A series of new experiments shows that analytic thinking can override intuitive assumptions, including those that underlie religious belief.
--snip--
"Obviously, this study doesn't prove the nonexistence of God. But it poses a challenge to believers: If God exists, and if believing in God is perfectly rational, then why does increasing rational thinking tend to decrease belief in God?"
MORE: http://www.scientificamerican.com/article.cfm?id=losing-your-religion-analytic-thinking-can-undermine-belief
See also...
Atheism: Analytical Thought Diminishes Religious Belief
http://news.gather.com/viewArticle.action?articleId=281474981295819
Study: Analytic thinking can decrease religious belief
http://religion.blogs.cnn.com/2012/04/27/study-analytic-thinking-can-decrease-religious-belief/comment-page-2/
Analytic Thinking Can Decrease Religious Belief, Study Shows
http://www.sciencedaily.com/releases/2012/04/120426143856.htm