When Paul B. Steinmetz worked among the Oglala Lakota in South Dakota, he prayed with the Sacred Pipe, conversed with medicine men, and participated in their religious ceremonies. Steinmetz describes the history, belief systems, and contemporary ceremonies of three religious groups among the Oglala Lakota: traditional Lakota religion, the Native American Church, and the Body of Christ Independent Church, a small Pentecostal group. On the basis of these descriptions, Steinmetz discusses the interdynamics of Pipe, Bible, and Peyote, and offers a model for understanding Oglala religious identity. Steinmetz maintains that a sense of sacramentalism is essential in understanding Native American religions and that the mutual influence between Lakota religion and Christianity has been far more extensive than most scholars have suggested.