The fields of personality and social psychology, with their focus on individual differences and human communalities, have much to offer the study of religious and spiritual development in adolescence. This review describes the ways McAdams and Pals’ comprehensive personality theory and Saroglou’s Big Four functional account of religion inform the scientific understanding of adolescents’ religious and spiritual development. These theories suggest religious/spiritual development of adolescents should be studied at three levels of personality (traits, characteristic adaptations, and narrative identity/objective biography) and account for the potential functions of religion in relation to behaving (moral), believing (cognitive), belonging (social), and bonding (emotional) across diverse cultural contexts. The utility of these theories for investigating adolescent religious/spiritual development is illustrated through description of empirical studies and lines of research based on methodologies commonly employed in personality and social psychology, including longitudinal studies, religious priming experiments, and experience sampling methods. Likewise, this review highlights areas for future investigation and provides specific suggestions for inquiry on adolescent religious/spiritual development, which include deploying experimental designs, merging narrative identity with identity status approaches, and adopting a more holistic view of traits through analysis of experience sampling data.