Encouraged by the teaching and example of the Apostles, the first Christians appointed bishops, presbyters, and deacons to govern their communities and ensure their development. These ecclesiastical leaders also had the responsibility of teaching and handing on their faith. Christians soon came under attack from the State, which saw the new religion as a threat; some Christians chose to die as martyrs rather than renounce their new faith.

In spite of this persecution, the Church spread rapidly throughout the Roman empire and beyond. Christian thinkers and writers emerged who were capable of conversing with the often hostile pagan and Jewish world. Further challenges were to be found within the Christian community itself, as some individuals began to develop doctrines that conflicted with the teaching of the Apostles. This was a time of flux and a time of trial. In response, Christians came to depend on the teachings of the bishops, especially those of the most important cities of the East and West.

The Christian Church was born in the high summer of the Roman empire into an immensely cosmopolitan world. Under the Roman peace, myriad peoples of Europe, North Africa, and the Middle East, their goods, their ideas, and their religions, all mingled in a way that they never had before.

For religion, in particular, it was a time of curious restlessness. The ancient Roman religion was still adhered to by most in the West, although many were influenced by sceptical philosophers. In addition a number of “mystery religions” seem to have been growing in popularity, and there was considerable interest in the Jewish religion, which had large settlements in many cities, including Rome itself.

Meanwhile the emperors had begun the cult of emperor worship, largely as a way of increasing the loyalty of their subjects; in modern terms, it was more a political than a religious practice. Julius Caesar was the first ruler to be deified, and, after him, so were all the emperors (some cared less about their divinity than others). People were obliged to attend the ritual sacrifices to the emperors as part of their religious duties, regardless of whether they believed in them or not. Romans also venerated the memory of their ancestors. And each religion could be held in combination with any of the others. One could have joined them all, if one had the money. It was therefore with a certain amount of suspicion that people regarded Christians and their refusal to take part in any religious observances but their own. Indeed, when disasters happened, they were apt to blame the impious Christians for angering their gods.

At first Christianity must have seemed just another new religion from the Near East, one among many. As such, it may have aroused the opposition of more conservative Romans such as the historian Suetonius (69–140), who said, “All that is loathsome comes from the East.” He viewed Christians as “a class of men given to a new and malevolent superstition.”

The birth of this new religion did not, however, seem that important – a merely local sensation in an obscure and backward province. So how did Christianity make any headway into society amid so much competition, given the precarious position of the Christians? How did the Church convert the early pagans who confronted Christianity with either apathy or hostility?

Perhaps it was the force of its teachings and of its preachers. Perhaps the story of the life, death, and resurrection of Jesus was so compelling that it challenged disbelief. For the hearer new to Christianity, its teachings were exciting. God, the God above all other gods, had become a human in the person of Jesus in order to persuade people to worship a loving God. Here was a compassionate deity none need fear. And the longing for immortality was answered by the promise of the risen Lord Jesus that his followers would join him in eternal life.

Many were also impressed by Christian community life, with its strong emphasis on family and on charity. Even some of the Church’s enemies commented on the Christians’ love – the Christian apologist Tertullian was pleased to assert that many pagans said, “See how those Christians love one another!” The unity of the Church was also a strength. Again, its enemies bear reluctant witness. The pagan critic Celsus, writing in c.170, commented of Christians: “Their agreement is quite amazing, the more so as it may be shown to rest on no trustworthy foundation.”

Maintaining unity was one of the main concerns of the Church’s leadership, now exercised by bishops, who drew their authority from what was later called “the apostolic succession.” This term refers to the fact that the first bishops had been appointed by the Apostles and had in their turn appointed successors, who were thus seen as the rightful heirs of the Apostles as the senior leaders of the Christian community. To keep the Church united, the bishops communicated with each other as much as they could. (Since the Reformation, many Protestants have disputed this view of the importance of the bishop; the pre-eminence of bishops was, however, unchallenged in the early Church.) In addition the Apostles had appointed others to help in the work of spreading the gospel, known as presbyters or elders, and had established the order of deacons to help the Church leadership in practical matters, such as dispensing charity. In the first centuries there were also deaconesses.

In the time of the Apostles, these leadership structures appear to have been fairly fluid. By the end of the first century, a standard pattern had emerged wherever the Church had become established. In each city one bishop was in overall charge of the Christian community; he was assisted by presbyters, who were increasingly known as priests. Deacons still assisted in practical matters, although their role diminished. After the Jerusalem church had been destroyed in the Jewish War of 66–70, the bishops of the leading cities of the empire, Rome, Alexandria, and Antioch, had the greatest prestige and influence among all the bishops.