Abstract
This paper provides an overview of theory in religion, aging, and health. It offers both a primer on theory and a roadmap for researchers. Four "tenses" of theory are described--distinct ways that theory comes into play in this field: grand theory, mid-range theory, use of theoretical models, and positing of constructs which mediate or moderate putative religious effects. Examples are given of both explicit and implicit uses of theory. Sources of theory for this field are then identified, emphasizing perspectives of sociologists and psychologists, and discussion is given to limitations of theory. Finally, reflections are offered as to why theory matters.