After considering the social and pastoral context in which Niebuhr began to develop his theology, some of the leading influences and dominant themes are identified. Through engaging with a gritty Marxian class analysis Niebuhr launched his attack upon the social idealism of so much of the Christian witness of his generation. In mid-life the critique of liberalism and his ‘Christian realism’ are informed by a wrestling with the Augustinian and Reformation traditions. Later still Christian realism gives way to a more pragmatic chastened liberalism. The dualism between the personal and social, which characterized Niebuhr’s ethics throughout his life, is critiqued and seen as part of a general pessimism that betrays the degree to which he remained marked by the Lutheran tradition.