Attachment theory deals with the development and dynamics of interpersonal affectional bonds. It also provides a framework for understanding individuals’ relationship with God, which is central to religion. We review basic concepts of attachment theory and survey research that has examined religion both in terms of normative attachment processes and individual differences in attachment. We cite evidence from cross-sectional, experimental, and longitudinal studies showing that many religious individuals experience God as a source of resilience (e.g. a safe haven and secure base). We also summarize proposed attachment-related developmental pathways to religion. Finally, we review research on religion and mental health undertaken from an attachment viewpoint and discuss future directions.