This dissertation is intended to fill a significant gap in the scholarship on slavery, race, and religion in the early modern Atlantic. Restoring a longue durée approach to the study of colonial history, it argues that there was a long, broad, and vibrant debate over the legitimacy of slavery and race. A central analytical tenet of this work is that religion and race were concepts linked from the early decades of colonization and developed in conjunction with one another. Enslavement predicated on heathenism brought baptism in particular to the center of the debate over whether African slaves could become free by adopting Christianity. Heathenism was central to early justifications of African slavery in the plantation colonies of the New World, and it also played a fundamental role in the construction, contestation, and articulation of racial categories, even if Christianity remained an important marker of colonial identity and social belonging.While the accommodation between the clergy and governors, planters, vestries, and colonial assemblies often conflated Christianity’s moral obligations with colonial self‐interest, religion and religious ideas also helped to challenge and undermine hierarchies based on race. Whether they were Jesuit priests, Anglican ministers, Quaker clerics, or Moravian evangelicals, missionaries of all backgrounds were able to provide a measure of spiritual and material relief to men and women who experienced human, material, and cultural deprivation on a massive scale. In these ways, enslaved and free people of African descent ascribed new meaning to Christianity that transcended narrow European definitions, challenging emergent notions of racial difference. Linking intellectual processes with social and political practices and institutions, this study attempts to resituate the Caribbean as foundational to the creation of a modern consciousness.