The Early Christian Writings were not written by the Apostles as were the books of the New Testament, but were written by leading Christians of the next generation who may have known some of the surviving apostles. These included epistles, some of them written to the same Christian communities St Paul has addressed a generation previously. Many of these epistles are written in the style of the Pauline epistles, sometimes using liturgical forms, sometimes weaving in and out of a prayer on behalf of communities they were addressing.
These translations are superior to the translations in the Anti-Nicene Fathers volumes, they are very easy to read. Quite unfortunately, the Shepherd of Hermas and the Fragments of Papias were omitted “for reasons of space.” Included are such gems as the Didache and the Martyrdom of Polycarp, and many epistles from Ignatius, Clement, and others.
These Early Christian writings were from the generation after the Apostles, which was one of the criteria for inclusion in the canon of the New Testament. The Didache is the earliest of these writings, and is set in the early Church era when evangelists such as Paul traveled from one church to another preaching the Gospels. A few of these writings are treasured simply because they are so few writings surviving from that first formative century, which means they are more valuable historically than theologically.