This article critiques the way in which the discipline of anthropology has construed Christianity, arguing that too narrow and ascetic a model of Christianity has become standard and questioning the claims of the ‘secular’ social sciences to have severed themselves entirely from their Christian theological underpinnings. The article is in conversation with other writers on related themes, including Jonathan Parry on Mauss's The gift, Talal Asad, John Millbank, and Marshall Sahlins. Here, however, established anthropological assumptions on topics including transcendence, modernity, asceticism, and genealogy are reconsidered through a fieldwork-based examination of American Mormonism, a religion which posits relationships between the mortal and the divine that are unique in Christianity. Despite their strong belief in Christ, Mormons have often been labelled as ‘not really Christian’ by mainstream churches. It is argued here that such theological position-taking is echoed in the social sciences and that this reveals some of its (that is, our own) unrecognized orthodoxies.