These studies in early church history cover various aspects of the church life of early Christians. They focus on the second century. During that period there was much in the practice and teaching of the church that corresponds to what is found in the New Testament, and during that time many new features developed which were to be characteristic of the later history of the church. Some later material which bears on the second century or which serves to complete the account of a development is brought into these studies. Some New Testament texts bearing on the topic are listed at the beginning of each chapter. There is, thus, a stress on historical continuity. We are talking about the same community of people, the same church, as existed in the New Testament. We are tracing out some features of its historical development through the second century.
-From the Introduction