Religiosity and spirituality have been an important component within the African American culture throughout U.S. history. Previous research has documented the importance of religion to African Americans, particularly in terms of coping with the negative experiences they face in the U.S. While many studies have focused on the positive impact of religiosity and spirituality on African American’s mental health, fewer studies have addressed change in African American’s religiosity over time, especially during the period when they transition from adolescence into young adulthood. Adolescence is a crucial developmental transition and can disclose a tremendous amount of knowledge about religious socialization and change in the life course. Utilizing data from the Family and Community Health Study (FACHS), a longitudinal study that examines African American families, this study extends the current state of the literature by examining and identifying multiple trajectories in African American adolescents’ religious development. Overall, there was a significant decline in religiosity during both adolescence and young adulthood. There was also individual variability in the change in religiosity during both developmental periods. Parental religiosity and deviant peer affiliation continued to have a significant impact on African American religiosity during both adolescence and young adulthood. Other sociocultural factors that predicted long-term growth, decline, or stability in their religiosity were also examined. Finally, implications of these findings as well as future directions for research on these relationships are discussed.