While scholars are slowly coming to realize that Kant’s moral philosophy has a distinctive theory of moral education, the import of religion in such education is generally neglected or even denied. This essay argues that Kant’s reflections on religion in parts II and III of Religion within the Boundaries of Mere Reason interpret religion specifically as one aspect of moral education, namely moral ascetics. After first clearly distinguishing between a cognitive and a conative aspect of moral education, I show how certain historical religious practices serve to provide the conative aspect of moral education. Kant defines this aspect of moral education as practices that render the human agent ‘valiant and cheerful in fulfilling his duties’ (MS, 6: 484). By this it is meant that certain practices can inspire moral interests either by justifying rational hope in living up to a certain standard of moral perfection (Christology) or by endeavouring to unite human beings in a universal, invisible ethical community that inspires cooperation rather than adversity (ecclesiology).