This book surveys the Greek fathers' interpretations of the Gospel of John from the earliest surviving commentary (Heracleon, c. 170) up to the early fifth century. It examines key themes and passages from the gospel and the varying methods of exegesis applied to them by different commentators, giving special attention to the contrast between the schools of Alexandria (notably Origen and Cyril) and of Antioch (Theodore of Mopsuestia and John Chrysostom). Maurice Wiles identifies the distinctive insights of each commentator and teases out the rich diversity of interpretations that flourished in this early period. This discussion is set within the wider context of early Christian thought, including the controversies between the Gnostic, modalist and monarchian heresies and 'orthodox' Nicene doctrine.