Attachment theoretical studies have increased our understanding of the socioemotional foundations for religious development. However, because these studies have been correlational and based on self-reports, they are vulnerable to concerns of self-presentation bias and lack of basis for causal inference. Three subliminal stimulation experiments were therefore performed, where activation of the attachment system was attempted by way of unconsciously administered separation stimuli. In Experiments 1 and 3 (N = 29 and 89), the separation stimulus alluded to God, and in Experiment 2 (N = 47), it alluded to mother. Responses were moderated by perceived attachment history with parents in all experiments. Participants with secure histories increased in religious attachment behaviors, whereas those with insecure histories decreased following attachment system activation compared with control stimulation. There also were suggestions of experimental group increase in proximity seeking in relation to God. The main conclusion supports correspondence between internal working models of parents and God.