There has been increasing interest in the evolutionary study of religion, but perfunctory fractionalization has limited our ability to explain how and why religion evolved, evaluate religion’s current adaptive value, and assess its role in contemporary decision-making. To move beyond piecemeal analyses of religion, I have recently offered an integrative evolutionary framework that approaches religions as adaptive systems. I argue that religions are an adaptive complex of traits consisting of cognitive, neurological, affective, behavioral, and developmental features that are organized into a self-regulating feedback system. Here I explore four advantages of this systemic approach to religion: it avoids definitional problems that have plagued the study of religion, affords a contextual understanding of religious belief, informs current debates within the evolutionary study of religion, and provides links to both the natural sciences and humanities. I argue that the systemic approach offers the strongest potential for real progress and broad application of evolutionary theory to the study of religion.