When we read the Creed of Constantinople of the year 381, which is generally called the Nicene Creed, we gain the unmistakable impression that we have travelled a long way from the opening verses of St. Mark's Gospel. This paper will consist of an attempt to answer the question, Was this journey really necessary? A number of negatives have been given to this question. It has been asserted that the doctrine of this creed was reached because the spirit of useless intellectual curiosity and of metaphysical speculation had gripped the theologians of the Church, so that the creed became only a stage towards ‘the bankruptcy of Patristic theology’ which was to be reached by the middle of the next century. It has been suggested, perhaps as a variant of the same argument, that this creed represents the capture of the original Judaeo-Christian message or gospel of primitive Christianity by a process of Hellenisation, a gradual approximation to late Greek, mainly Platonic, philosophy. The theory has even been put forward with a wholly misplaced confidence that the doctrine of the Trinity was produced in order to guarantee a celestial order and security corresponding to and supporting the order and security represented by the Christian Emperor himself. These are all explanations of the doctrinal journey which in one way or another see it as a superfluity or a deviation.