Defenders of the Faith

The second century of church history began with the church working to gain its footing and deal with the hostile Roman Empire, and that helps explain why many of the earliest post-Apostolic Christians lack theological depth—people were focused on surviving. Notable exceptions exist. First Clement, a letter written by an elder in Rome around the year AD 100, and the Epistle to Diognetus, an anonymous text written as early as 130, both anticipate the fully worked-out doctrine of justification by faith alone.

In the main, the notable figures of the immediate post-Apostolic period were the second- century apologists—defenders of the faith. The most significant of the apologists was Justin Martyr, so named because he was martyred during the reign of Emperor Marcus Aurelius. Justin's defense of the faith was typical of the apologists of the time. To the Jews, he stressed how Jesus fulfilled Old Testament prophecy. He confronted pagans, proclaiming the rationality of Christian belief and the sound ethics of the Christian religion, and he mocked idolatry in a manner reminiscent of the old covenant prophets (Isa. 44:9-20). In many ways, apologists like Justin model how we should defend the faith today in their stress on the reasonableness of Christianity, and in looking to Scripture to define Jesus' identity.

With Irenaeus (130-200) we have the first great theologian of the post-Apostolic period. Irenaeus, who in his youth knew Polycarp, is best known for his work Against Heresies, in which he confronts the early church heresy known as Gnosticism. Various beliefs fall under the umbrella of Gnosticism, but the core of the heresy was that the material world is bad, that the God described in the Old Testament is not the God and Father of Jesus Christ, and that salvation is obtained not by atonement but by means of "secret knowledge." Gnostics said that this hidden knowledge, or gnosis, consisted in traditions that Jesus gave in secret and that had been passed down in secret in the Gnostic community. Irenaeus fought this heresy by pointing to the fact that if such knowledge had been revealed, it would have been revealed publicly and would have been preserved in the visible church. For Irenaeus, the bishop had the chief responsibility in preserving the gospel message, but his understanding of bishops was not what the later Roman Catholic and Eastern Orthodox traditions would embrace. At the time, a bishop was essentially a faithful pastor whose main work was teaching. He depended on many associates in ministry to help in his work.