John Baillie was born on 6 March 1886 in Gairloch, Scotland. A minister, John and his brother, Donald, the ‘Baillie Brothers’, were the greatest ‘mediating’ theologians of their era. Lecturer in Moral Philosophy at Edinburgh and Pastoral Assistant at Broughton Place, he fought in France during the First World War. Afterward, he became Chair of Christian Theology at Auburn Theological Seminary. In 1930, he was appointed Roosevelt Professor of Systematic Theology at Union Seminary, and four years later, he returned to Edinburgh as Professor of Divinity and Principal of New College.
In 1957, he was named Companion of Honour to the Queen. An ecumenist, he volunteered at the Edinburgh Mission Conference, served the Faith and Order Movement, and was Founding Member of the British Council of Churches. Notable works include The Interpretation of Religion (1928), The Place of Jesus Christ in Modern Christianity (1929), Our Knowledge of God (1939), Invitation to Pilgrimage (1942), What Is Christian Civilization? (1945), Natural Science and the Spiritual Life (1952), The Idea of Revelation in Recent Thought (1956), and A Reasoned Faith (1963).