Christians living in the Roman empire during the first four centuries after Christ struggled with the extent to which they should recognize and accept imperial authority. In the fifth century A.D., Augustine of Hippo definitively enabled Christians to support Roman power directly by showing how the purpose of the state could be consistent with the purpose of Christianity. Christians could and should submit to the rule of Roman law and live within a society characterized by a plurality of religions. But as David Lopez demonstrates in Separatist Christianity, the four centuries before Augustine witnessed a very different and far less nuanced doctrine. Through a close reading of canonical writings from the second and third centuries, he finds a Christianity that advocated a complete separation from the material and pagan Roman world. Incited by state persecution and cognizant of the fragility of their communities, church leaders and prominent Christian thinkers exhorted their followers to reject any accommodation with the Roman empire. To recognize imperial authority, they contended, would be to apostatize from the truth of Christianity. Examining how ideas of martyrdom, apocalypse, and separation from the social and political world of Rome developed between the destruction of the Temple in 70 and Constantine's conversion in 312, Lopez finds a coherent and consistent anti-Roman sentiment in early Christianity. This radical agenda appears not only in the works by and about martyrs but also in the exegetical, disciplinary, and apologetic texts. By establishing the coherence and ubiquity of this separatist philosophy, Lopez offers a fresh new interpretation of the history of the early church.