The suppression thesis is the theological claim that theistic non-belief results from culpable mistreatment of one’s knowledge of God or one’s evidence for God. The thesis is a traditional one but unpopular today. This article examines whether it can gain new credibility from the philosophy of self-deception and from the cognitive science of religion. The thesis is analysed in terms of the intentionalist and the non-intentionalist model of self-deception. The first proposed model views non-belief as intentional suppression of one’s implicit (...) knowledge of God. It is less feasible psychologically but has a good theological fit with Paul’s and Calvin’s versions of the thesis. This model also helps the argument for the culpability of non-belief. The second model views suppression as a process of subconscious motivated reasoning driven by a desire to avoid an uncomfortable truth. It fits Pascal’s view that one’s desire for or against God determines whether one sees general revelation as providing sufficient evidence for God. There is some empirical and anecdotal evidence for both models, but obvious cases of non-resistant non-belief present a major problem for the suppression thesis. Also, it is hard to see what might motivate anyone to deceive oneself about God’s existence. (shrink)