‘What has Athens to do with Jerusalem? What agreement is there between the Academy and the Church?’ Tertullian’s outburst is still being echoed in some quarters, notably in the Biblical Theology School, which tries to minimize the influence of Greek thought on the Christian tradition. There are some circles in the World Council of Churches which would use its new formula of doctrinal orthodoxy to exclude the Unitarians and Quakers. Yet as Ernest Scott wrote, ‘Liberty is inherent in the Christian Faith, and liberty always makes for difference’. Athens or Jerusalem? (first published in 1965), based on the Minns Lectures of 1963, is unique as it gives a comprehensive survey of Christian thought and is designed to show that it is an amalgam of elements from both Athens and Jerusalem, and other sources as well. It concludes with a consideration of the question: how far is it possible to diverge from the mainstream of Christianity without ceasing to be Christian?