This article reviews scholarship on the religious lives of slaves. The emergent field of Atlantic history has profoundly influenced scholarship on the response of African slaves to Christianity, the nature of black Christianity in the Americas, and the ways that black Christianity differed from that of whites. The study of the religious lives of enslaved peoples in the Americas has benefited enormously from the work of historians and anthropologists who have studied Africa during the centuries of the Atlantic slave trade. In articles and books, John Thornton, most notably, a historian of pre-colonial Africa, has argued for the need to understand the religious lives of Africans before their enslavement and forced relocation to the Americas. Thornton's work underscores that many enslaved Africans were in fact believing and practicing Christians before the Middle Passage. This recognition has implications for the ways in which African Christianity informed slave life and culture in the New World.