Mapping the religious field of present-day Western cultures such as America and Europe requires a synopsis of perspectives: There are, on the one hand, classical ways of defining religion in theology, sociology and psychology and also established sociological models of the religious field; and there are, on the other hand, recent changes in how people on the street implicitly and explicitly understand themselves and behave: Many are reluctant to identify as religious persons, but self-identify as “spiritual” or “spiritual, not religious.” In this text we introduce our conceptualization of religion and of the religious field. Key concepts of religion are transcendence and ultimacy. For structuring the religious field, we attend to the distinction between vertical and horizontal symbolization of transcendence and ultimacy, and to the distinction between institutional mediation and individual immediacy.