The first segment of time delineated by ecclesiastical historians in their attempt to analyze the nearly two millennia of the Church’s existence is called the Early Church. Scholars generally mark this period as beginning on Pentecost Sunday (circa A.D. 30) and concluding with the Edict of Milan in 313.
These three centuries are usually subdivided into two eras: the first is called the “Apostolic Age,” from 30 to 180, and is of course dominated by the towering figures of the twelve Apostles, the disciples of Jesus and their immediate followers.
Sometimes called the “primitive Church,” this Apostolic Era was noted for the extraordinary missionary expansion of the Church, the development of the canon of Scripture, the formation of a rudimentary hierarchical structure, the articulation of the fundamentals of the Faith through creeds to counteract heresy, internal and external struggle, opposition and persecution, and the efforts of the Christian community to arrive at a way of living with the Roman, Greek and Jewish cultures.
The writings, worship and structure of the Church in this Apostolic Age show the effects of these three cultures upon evolving Christian thought and practice.
The second subdivision is usually referred to as the “sub-apostolic Church,” 180–313, which is characterized by numerical growth, geographical expansion, severe persecution, theological activity (especially in the cities of Antioch and Alexandria) and the growing attention to the problems presented by the world, especially the Roman Empire. (8:34)