At the heart of modern liberalism is an ideal of religious equality, according to which religious minorities should be granted the same civil and political rights as the religious majority. So basic is this ideal to modern liberalism that liberals often take it for granted. This is a mistake: in fact the case in favor of religious equality is far from obvious. In order to stir liberals from their complacency, I define a stark challenge to religious equality, one I call the challenge of salvific exclusivism. Salvific exclusivists are people who believe that salvation lies in their religion alone; thus they believe that religious error threatens the eternal welfare of their fellow citizens. Religious error, though, flourishes in a regime o...