To understand the Christianisation of Egypt as well as the conflicts with native religion that this process entailed, we need to make some tentative distinction between the Christianity of texts and the Christianities assembled locally in villages. If the ancient gods and their shrines were often demonised, the new Christian worldview also depended upon familiar notions of harmful and beneficial power, ritual efficacy, and communication with divine beings. The author calls this inevitable process of mediating new ideologies within traditional schemes of ritual power syncretism, but only to the extent that it involves indigenous local agency and a genuine engagement with the authority of the new worldview, and not in the older sense of pagan survival or native misunderstanding. A growing intolerance among Christian leaders for Egyptian temple cults from the late fourth century probably arose with a revival of martyrological lore. The secret corridors and austere priestly rites once romanticised in Hellenistic literature now became the loci of sorcery.

Egyptian Christianity began in Alexandria, by far the greatest of the many cities founded by Alexander the Great. Jewish immigration into Egypt from Palestine had begun as early as the sixth century BCE, and Jews flowed into Alexandria in large numbers, with the result that the Alexandrian Jewish community became important in all of the diaspora. Christian organisation in Alexandria exhibits a continuity with Alexandrian Judaism, especially in the form of the presbyterate. Demetrius played a crucial role in the development of the Egyptian Christianity. The 'Catechetical School' of Alexandrian Christian tradition came into being only in the early third century as a result of the growing authority of bishop Demetrius. In the third century a new form of Gnosticism made its entry into Egypt, Manichaeism, which eventually became a world religion in its own right. Monasticism as an institution has played a greater role in the history of Egyptian Christianity than in that of any other regional church.