At some point during the early history of rabbinic Judaism there emerged a tripartite Hebrew Bible known by the Hebrew acronym TaNak, which stands for Torah, Neviim, Ketuvim, that is, Pentateuch, Prophets, Writings. This was similar to but different from the first testament of the double testament Greek Bibles being used at the same time in Christian communities throughout the Graeco-Roman world. Several canons of Christian Scripture of differing contents exist, ranging from the eighty-one-book Ethiopian Orthodox canon to the sixty-six-book Protestant canon. A number of references in ancient Jewish literature indicate the beginning of the Jewish tripartite canon, starting with the Torah and the Prophets. A tenet of rabbinic Judaism that separated it from other forms of Judaism was the rabbinic belief that prophecy or divine revelation/intervention in history ceased in the Persian period. Adaptability and stability must balance each other for the canonical process to be effective.

By the mid-third century, have clear evidence that a Christian teacher like Origen could offer a complete philosophical education, which paralleled that which was offered in schools all over the Graeco-Roman world. Teaching and learning were characteristic of Christianity from the beginning. It is plausible to suggest that some early Christian communities were modelled largely on the Jewish synagogue, an organisation that had both religious and 'school'-like properties. Teachers, as well as prophets, have a prominent role in texts coming from the earliest churches, and a teaching function is assumed for bishops. Origen's love of philosophy, together with his conviction that philosophy was the foundation of true piety towards God, was what persuaded Theodore to stay in Caesarea and give up his homeland and friends, as well as his intended career. The contribution of Origen was to stimulate the development of a genuine intellectual tradition within Christianity. Scripture became the crown of his Christian paideia.

To speak of early Christian self-definition is to recognise that the sense of self always implies differentiation from one or more 'others'. This chapter identifies those significant 'others' as the 'Jewish matrix' and the 'Graeco-Roman world', differentiation from 'Gnostic' groups is arguably different in kind. Paul's was not the only model developing during the first century. Although constrained by the quasi-biographical gospel genre, Matthew denies any rupture with a genuine faithfulness to the past, either in his presentation of the person of Jesus, whom he describes in ways recalling Moses. Now that rabbinic Judaism is no longer taken as the controlling norm for any reconstruction of Jewish thought throughout the period one can also recognise that Christian theology's attempts to address the Hellenistic world continued to owe much to the earlier and perhaps continuing efforts made by Jews to speak of their God in the same context.

This chapter analyses a crucial moment in the second century of the formation of a 'Christian' discourse and, indeed, of the construction of 'Christianity' itself. Justin Martyr was not the first to take up the question of self-definition vis-à-vis the Graeco-Roman world, and he would certainly not be the last, but he was surely one of the most influential to do so. Taken together, Justin and Celsus signal a turning-point in the construction and contestation of Christian discourse. Justin's notion of an ancient Mosaic philosophy on which the Greek philosophers depended betrays the influence of contemporary ideas about the history of philosophy. The distortions and corruptions with which contemporary Platonism was riddled could be compensated for through a process of triangulation among the doctrines of Plato, the precepts of Pythagoras and the institutions of the most ancient 'barbarian' peoples. The feature of Greek philosophical theology was the attempt to reinterpret traditional religion in light of a form of monotheism.