Around the world, publics confronted with terrorism have debated whether Islamic faith gives rise to a uniquely virulent strain of non-state violence targeted at civilians. These discussions almost always conceive of “Islam” in general terms, not clearly defining what is meant by Islamic religious faith. We engaged this debate by designing and conducting a large-scale public opinion survey in Pakistan that measures multiple elements of religiosity, allowing us to separately consider the relationship between support for militant organizations and (1) religious practice; (2) support for political Islam; and (3) “jihadism,” which we define as a particular textual interpretation common to Islamist groups espousing violent political action. We also measured support for militant organizations using a novel form of an “endorsement experiment” that assessed attitudes toward specific groups without asking respondents about them directly. We find that neither religious practice nor support for political Islam is related to support for militant groups. However, Pakistanis who believe jihad is both an external militarized struggle and that it can be waged by individuals are more supportive of violent groups than those who believe it is an internal struggle for righteousness.