Authors in the psychoanalytic tradition, in particular Freud and Jung, have engaged with religious topics. Famously, Freud views religious belief as a case of projection. Jung, meanwhile, adopts a more sympathetic position in relation to religion. Unsurprisingly theologians have frequently expressed a preference for Jung as an interlocutor, rejecting Freud as so hostile to religion as to possess no theological potential. I argue that this is a mistake. The Freudian approach to religious belief contains rich resources for purifying our God-concepts. We do indeed frequently project our wishes and desires onto God and other religiously inflected entities or concepts (such as the afterlife). This represents, in biblical language, a form of idolatry. Given that a central task of theology ought to be the overcoming of idolatry, engagement with Freud's critique can serve us in this end. Theology engaged with Freudian psychoanalysis has, then, the potential to be a form of negative theology, standing in a venerable tradition.