Criminologists and sociologists have long examined what governs the prison social world. However, prior studies have generally overlooked how religion organizes and stratifies life in prison. Drawing upon 12 months of ethnographic fieldwork inside a U.S. state women’s prison, this dissertation demonstrates that religion is central to many inmates’ daily activities. It contributes to their freedoms and privileges while also constraining their choices behind prison walls. Religion is woven into the fabric of prison life: threaded through material benefits, the prison social order, the meaning of incarceration, and even inmates’ sexual identity. The extent to which inmates’ experience is shaped by religion depends on their denominational affiliation and level of practice. As such, religion operates as a tool that leverages inequality among the prison population. Religious messages cast imprisonment as part of God’s plan, simultaneously providing hope and a neoliberal framework of individual responsibility, but always in the shadow of demographic patterns of mass incarceration. Religious messages are noticeably silent on issues of race and social class, while dictating acceptable behavior around gender and motherhood that conceal normative racial and class expectations. Profoundly shaping how women view their incarceration, religion stretches into even the most private spaces, that of women’s sexuality. In an environment where being “gay for the stay” is common, religious programs function as a space in which inmates can spend time with their romantic partners. However, conservative Protestant programs encourage inmates to relinquish homosexual relationships and instead embrace femininity and submission, leading to conflict between inmates who subscribe to these ideals and those who do not. Finally, while participation in religious programs is a mechanism of adaptation, improving inmates’ quality of life by providing material resources and social support, it is also a mechanism of inequality, given that these resources are unavailable to secular inmates, and their distribution depends on denominational affiliation. Overall, this dissertation demonstrates how religion propagates inequality within an already disadvantaged population.