This article analyzes Michel Foucault’s reading of early Christianity, focusing on the investigation of the constitution of Christian subjectivity through the problematics of obedience and the will. The analysis explores the moral and theological systematization that defines how obedience becomes an absolute end, as well as the Augustinian theorization of libido and original sin. Thus, it seeks to provide a grid of intelligibility for Foucault’s analyses of Christianity in the early centuries.