A life span model of development provides the framework for examining the relation between religion and personality in aging persons. This article emphasizes the interplay of constancy and change in adult religious life. Important contextual factors that influence religion and personality are noted. A discussion of generativity and ego integrity shows how the maturing personality can embrace religiously motivated acts of justice and mercy as well as a deepening of spiritual life. Also discussed are the ways religion encourages generativity and ego integrative processes. The article concludes with suggestions for future studies of religion, personality, and aging utilizing a life span model of development.