This book opens by establishing the substantial convergence in reflection on Christian tradition proposed by a 1963 report of the Faith and Order Commission (of the World Council of Churches) and the teaching of Vatican II (1962–5). Despite this ecumenical consensus, in recent years few theologians have written about tradition, and none has looked to the social sciences for insights into the nature and functions of tradition. Drawing above all on sociologists, this work shows the difference that tradition makes in human and religious life. In the light of the divine self-revelation that climaxed with Jesus Christ, the central characteristics of tradition are set out: in particular, its relationship to and distinction from culture. The risen Christ himself is the central Tradition (upper case) at the heart of Christian life. All the baptized faithful, and not merely their ordained leaders, play a role in transmitting tradition. The ‘sense of the faithful’ amounts to a ‘sense of the tradition’. The essential, if invisible, agent of tradition remains always the Holy Spirit. Scripture and tradition function in mutual dependence, as shown by the emergence of the creeds, the image of Christ as the New Adam, and the doctrine of justification (on which a 1999 joint declaration shows substantial agreement now reached by Lutherans, Roman Catholics, and others). The full context of Christian life and history focuses the relationship between Scripture and tradition. The book deals with the challenge of discerning and reforming particular traditions. A closing appendix shows how modern studies of memory—above all, collective memory—can illuminate ways in which tradition works to maintain Christian identity and continuity.