This paper longitudinally examines the role of parents in the process of faith formation from ages 13 to 19. Mixture regression showed that the adolescents divided into four classes based on how their parents' religiosity related to their faith progression. Classes were distinguished by religiosity level at age 13, and generally followed parent religiosity. Within class, parent religiosity had a positive relationship with adolescent faith development in 2 classes (59.3% of the sample) and in 1 class parent religiosity had no relationship to adolescent religiosity (19.5%). In a fourth class, mothers' religiosity was negatively related to faith development (21.3%). Positive relationships between parent and adolescent religiosity were observed when adolescents had high religiosity at age 13. When adolescents were low on religiosity at age 13, parent religiosity had a negative or no relationship with adolescent religiosity. Among other factors, faith transmission was most prominent in families with high levels of family religious practices and among adolescents more physiologically sensitive to the environment. The negative relationship between parent-adolescent religiosity was associated with less authoritative mothering. These findings are conceptualized within Bronfenbrenner's bioecological theory, describing how parents differ in their influence both at the starting point of adolescent religiosity and its trajectory over the adolescent years.