Kreider begins chapter one of The Change of Conversion and the Origin of Christendom by identifying the essence of conversion as change, and he then seeks to understand the types of changes that took place in conversion during the earliest centuries of the church. After noting the ambiguous New Testament witness on this matter (due not to confusion or contradiction but simply lack of information), he turns to the stories of Justin and Cyprian in order to better understand what conversion looked like in the church shortly after the time of the apostles.
Justin, who lived in the early to mid second century (AD 100-165) and eventually died for his faith, gives two accounts of his conversion. In the first he tells of his studies in various philosophies and eventual interaction with a fairly simple Jewish Christian who told him about Jesus and how Jesus came as the climax of God’s promises to the world (especially through the prophets). When Justin came into contact with Jesus’ words, he saw that they “possess a terrible power in themselves, and are sufficient to inspire those who turn aside from the path of rectitude with awe” (3). In his second account he talks about how in spite of the nasty things people said about Christians, he was impressed with their fearless witness in the face of persecution and death. Through these influences, he too became a Christian.
This probably happened in Rome, where he also began to teach about the Christian faith, perhaps providing catechetical instruction (training in discipleship) for people seeking baptism. He taught about God’s character as revealed in creation and in God’s promises through the prophets. And from this foundation of belief, he turned to behavior, where he admitted that hearers would struggle to reject the lures of “necessity” (compulsion, addiction) and fight diligently for their salvation. He saw this fight with sin as a resistance of demonic power, most notable in four areas: sex, occult (religious magic), money, and power. His typical formula: “We who once . . . (delighted in fornication, practiced magic arts, took pleasure in increasing our wealth, hated and killed one another and would not live together with those different from us) now . . . (rejoice in continence, trust God alone, live out of a common purse, live with and pray for our enemies).”
For Justin, both beliefs and behavior are absolutely vital. Converts must be “persuaded and believe that the things we teach and say are true,” and “those who are found not living as Christ taught should know that they are not really Christians, even if his teachings are on their lips.” Indeed, would-be converts must “promise that they can live” according to the teachings of Jesus. So there is a definite belief piece as well as a behavior emphasis, and the context for the whole is belonging. It is in the church that “we who once . . . now . . .” The church is this we within which a new life is possible. Justin freely admitted how difficult were the teachings of Christ, but affirmed that while for humans alone these things are impossible, with God – which, for him, also means with God’s people – all things are possible.
My main observation from this is that conversion was taken seriously and they didn’t hesitate to ask much of newcomers to the faith. There was a period of focused teaching and there were serious expectations about changes in behavior, all within the context of participation in the life of the community (which was still house church based). People weren’t just becoming a better version of their old self; they were being asked to take on a fundamentally different way of life.