Though Hume was a notorious atheist, Dialogues Concerning Natural Religion has a strong fideist bent to it. Fideism has been a popular position in the philosophy of religion. It claims that religious belief cannot be based on reason, but must be based instead on faith. According to fideism, therefore, the first fundamental step toward Christianity is skepticism: it is not until we undermine our trust in the power of reason, that we can come to worship God in the proper way, by opening ourselves up to revelation. In the context of the Dialogues fideism can be thought of as the opposite of empirical theism.
The fideist position is best represented in the Dialogues by the character of Demea. Demea is an orthodox Christian, who believes that God cannot be comprehended or understood at all, much less through reason. But the skeptical Philo also adopts a fideist position, particularly in the last chapter of the book. Whether this means that Hume himself was sympathetic to fideism has been a huge topic of debate among scholars ever since the book was first published.