Three factors – Rome’s peripheral position, its rivalry with other sees, and the role of Roman aristocrats – shaped the ecclesiastical policy of the popes in late antiquity. Their claims to ecclesiastical authority across the empire were based on the reputation of the City of Rome. In addition, the Petrine tradition became crucial for the representation of late antique popes. From an Eastern perspective, however, they were no more than the patriarchs of the West. As they were not under the direct grip of the emperor, the popes possessed more agency than Eastern bishops, but this made it more difficult for them to influence imperial politics directly. Therefore, they composed treatises about the relationship between emperor and bishop, which answered concrete challenges, but were interpreted as fundamental texts later. In retrospect and in retrospect only, late antique papacy was the first step of a scale towards universal papacy.

This book does not offer a linear history of Christianity during the first centuries ce but attempts to show how Christians met the expectations and challenges of their environments. I am perhaps exceedingly cautious in my analysis of the social history of Christians because the rather qualitative evidence of the sources on the individual actors does not seem to me to provide a sufficient basis for quantitative analyses. In addition, I do not give an explanation for the success of Christianity but offer many reasons why Christians were successful in certain contexts.

It is striking that Christians were so successful. They had internal dissension; lacked relics; had no common temple; came from less educated classes and the periphery of the empire; Jews and pagans harassed, even persecuted them. Because they did not offer sacrifices, excluding them from offices and festivals, and were unable to maintain certain family traditions they appeared antisocial. Yet Christ-followers succeeded in winning over non-Jews as well. The persecutions welded Christians together, and martyrs served as role models, even to those who had manifested weakness. In areas such as sexual morality, Christians sought to demonstrate that they were superior to contemporaries of other faiths. They also formed transregional networks. The opportunity to gain prestige in Christian communities also attracted people. Various forms of authority competed with each other, especially the charismatic and spiritual authority of those who excelled in ascetic practices. That in the end monarchical bishops were to become the decisive figures in Christianity was by no means clear from the beginning. That Roman emperors would support Christianity was an unlikely development that changed Christianity significantly. But the tradition of a defiant piety that defined the beginnings was not lost, so that Christianity continued to renew itself.

Christians oriented their lives towards the expectation of a life in the hereafter and yet had to orient themselves in this world. This resulted in very different attitudes. While some were fundamentally anti-family or, rather, against sex in general, others thought about what it meant to have a Christian marriage. While some wanted to participate in the pleasures of everyday life, others rejected this. All tried to live a humble life and do good works, especially towards the poor, orphans and widows. Penance was an institution that allowed Christians to be absolved of their sins, but it also allowed bishops to gain power, albeit in varying degrees Therefore, the question of a Christian way of life was always controversial.

Very few Christians rejected the Roman Empire in principle; rather, many saw it as a prerequisite for their mission because of the peace that the Empire created. Nevertheless, conflicts arose: Few understood why Christians, who worshipped only one God, did not want to sacrifice. In the eyes of contemporaries, this could provoke the gods and endanger social peace, and was a reason for persecution in many places. Many Christians made sacrifices under pressure, but some also became martyrs who gained great prestige. Meanwhile, some Christians entered the service of the state and held public office or became soldiers. They often made compromises that strict Christians criticised. Some seemingly enjoyed the glamour of public duties. That Christians would dominate the empire was by no means a foregone conclusion even at the end of the third century, at the time of Constantine the Great.

Since late antiquity, bishops have been regarded as possessing the highest authority among Christians. But there was no linear path leading there. Rather, there were different bearers of authority among Christians: James, as the respected brother of Jesus, was a key figure at the beginning; intellectuals were able to gain importance as teachers, prophets also appeared after Jesus, among them many women; widows and virgins attained a special position; finally, the authority of ascetics increased. Basically, authority could be derived from an office within the church or from personal charisma, which was considered God given. Good bishops tried to combine both, but charismatics could always challenge them and would continue to do so throughout the history of Christianity.

The ignominious death of Jesus on the cross was the starting point of the history of Christians. It could have meant the end of the followers of Christ, especially because soon the body of Jesus also disappeared. However, the Christians succeeded in interpreting the events for themselves by speaking of the resurrection of Christ and cultivating the expectation of his return (parousia). Such ideas seem strange to modern observers, but they were apparently convincing for enough contemporaries that the followers of Christ survived. However, they were continually dependent on words, because relics were initially lacking and only memories could help spread faith in Jesus.

The aim of the book is to show, from a historian’s point of view, how strange the early Christians must have seemed to their contemporaries and what difficulties they faced in living their faith in a non-Christian world. In doing so, it will become clear that Christians chose a huge variety of paths and that there was no linear progression toward later forms of Christianity. Therefore, the seemingly familiar early Christians are strange even to modern observers. In order to make clear their diversity and strangeness, I do not follow chronological order, but treat the subject matter according to different topics, in four main chapters. The first illustrates the difficulties for Christians to position themselves between Jews and pagans, the second the dispute over forms of authority within the Christian group, the third the challenges of everyday life for Christians, the fourth the relationship to the political system up to Constantine the Great, who turned to Christianity. In addition, I discuss the methodological and theoretical issues involved.

Jesus was a Jewish preacher and, for some Jews, a Messiah. His first followers lived in Jewish contexts. Only gradually did the differences between Christians and the followers of other religions become visible. Thus, there was a parting of the ways between Christians and Jews, but it was never complete. Jews and Christians always observed and influenced each other. Christians also set themselves apart from the many groups they called pagans. Although they believed in the existence of the gods, they considered them to be demons. They also developed their own rituals and created places where they met, so that Christianity became increasingly recognisable as a religion in its own right.