This book deals with the social gospel and one of its leading proponents in twentieth century Australia, the Anglican bishop of Armidale, New South Wales, from 1929 to 1964, John Moyes. It is an investigation and assessment of the career of Bishop Moyes as a study in Christian social engagement. It concerns his vision for the role of the church in society and his contribution to that effect. It is not a biography of John Moyes. Neither is it an exhaustive history of the social gospel movement in Australia or anywhere else, although they both feature prominently throughout. Bishop Moyes was a highly articulate public debater who participated in several of the critical episodes in Australian history during the twentieth century. The reader will find within the pages of this book discussion of highly contentious issues such as the attempt to ban the Communist Party of Australia in 1950 and 1951, the decision to commit Australian troops to the Vietnam War in 1965, and the Christian response to state-legitimised violence. Moyes is placed in context with some of the most notable Christian spokespeople on social and political issues in the twentieth century, such as Walter Rauschenbusch, Ernest Burgmann, William Temple, George Bell, Dietrich Bonhoeffer, Reinhold Niebuhr, Martin Luther King Jr., and Andr Trocm. It is argued here that John Moyes made intelligent, prescient, and compassionate contributions to many of the issues to which he turned his mind, but that, like most others before or since, he was unable to find a solution to the theological and moral challenges raised by the perceived threat to Australias sovereignty during World War II. This book challenges the view that when national sovereignty is threatened, the Christian response must be to support the governments call to war.