This work sets out to explore a fundamental problem in the early centuries of the Christian era, namely, to what extent the Christian faith could legitimately make itself intelligible in the Greco-Roman world by the use of the categories of ancient philosophy. For some such as Justin Martyr, Christianity was simply the best and most perfect philosophy. For others there was a danger that in attempting to give philosophical expression to Christianity the biblical understanding of Christ would be negated and thus the Christian message distorted. Was it possible in practice for Christians in the early centuries to reconcile the biblical and philosophical approaches to the Christian God? Special attention is given to the writings of Justin Martyr, Origen and Augustine. In addition in an epilogue there is a discussion of the problems posed in the Middle Ages by the ‘rediscovery’ of Aristotle and what Aquinas made of the dialogue between ‘faith and reason’.