Persecuted by the Sanhedrin, the Christians very soon parted company with the Synagogue. From the very beginning, Christianity was universal, that is, open to the Gentiles, to whom the rules of the Mosaic laws did not apply.

1. First Expansion

‘A disciple is not above his teacher’ (Mt 10:24), Jesustold his disciples. TheSanhedrin declared Jesus a criminal to be punished by death for claiming to be themessiah, the Son of God. It was only logical for the Jewish authorities to be hostile to his Apostles, when they proclaimed that Jesuswas risen and confirmed their preaching by various public miracles.

Sanhedrin tried to silence them, but Peterreplied to the high priest, ‘we must obey God rather than man’ (Acts 5:29). TheApostles were put under the lash, but neither threats nor violence could silence them, and they left rejoicing ‘that they were counted worthy to suffer dishonor’ for the name of Jesus. The death by stoning of St. Stephen the deacon marked the beginning of severe persecution of Jesus’ disciples. The cleavage between Christianity and Judaism grew steadily deeper and more overt.   

In contrast with the national character of the Jewish religion, the universalism of Christianity soon expressed itself. Disciples of Jesus, in flight from Jerusalem, reached Antioch in Syria, one of the great cities of the east. Some of them were Hellenists, with an outlook more open than that of Palestinian Jews, and they began to proclaim the gospel to the Gentiles. In cosmopolitan Antioch, the universalism of the Church became patent; and it was there, for the first time, that Christ’s followers were called Christians.

2. Universality of Christianity

The universality of the redemption and of the Church of Jesus Christ was formally confirmed by a miraculous event in which the apostolate Peter was the protagonist. The extraordinary signs surrounding the conversion of Cornelius, a centurion at Caesarea, and his family, cleared up any doubts had on this subject; as he put it, ‘Truly I perceive that God shows no particularity, but in every nation anyone who fears him and does what is right is acceptable to him’ (Acts 10:34-35).

The news that Peter had given baptism to uncircumcised Gentiles caused consternation in Jerusalem. It was difficult for many Jewish Christians, attached as they were to their old traditions, to understand how Gentiles could be members of the Church. They felt that for Gentile converts to have access to salvation they needed at the very least to be circumcised and to keep the regulations of the law of Moses. This naturally disturbed Christians of Gentile background, so the Church was forced to examine the whole situation of the relationship between the old law and the new law, and to affirm unequivocally the Church’s independence of the Synagogue.

3. The Council of Jerusalem

To discuss these fundamental problems the so-called ‘council’ of Jerusalem met in the year 49. At this assembly Paul and Barnabas spoke on behalf of the churches of Gentile background and bore witness to the wonders God had worked among them. Peter once again spoke with authority in favor of Christian’s freedom vis-à-vis Jewish legal observances.

On the proposal of James, bishop of Jerusalem, the council agreed not to lay any unnecessary burdens on Gentile converts: they should only have to obey a few simple rules: keep away from fornication and, as regard the old law, abstain from meat which was strangled or had been sacrificed to idols (Acts 15:1-33), Christianity and Judaism. Jewish Christians in Palestine still followed their own style for a while, but they were a minority within a Christian Church ever more widespread throughout the Gentile world.     

4. The Promoters of the Expansion

The great promoters of the spread of Christianity were the Apostles, acting in obedience toChrist’s commandment to proclaim the gospel to all the nations. Due to lack of historical documents it is difficult to find out much about the missionary activity of most of theApostles. We do know that the Apostle Peter, on leaving Palestine, made Antioch his base (there was an important Christian community there already). It is possible that he also lived for a time in Corinth, but his final base was Rome, the capital of the empire; he was the first bishop of the Roman Church. In Rome he underwent martyrdom in the persecution unleashed by Emperor Nero (c. 64).

John the Apostle, after staying a long time in Palestine, moved to Ephesus, where he lived for very many years, so much so that the churches of Asia regarded him as their own Apostle. Very early traditions speak of apostolic activities of James the Greater in Spain, ofThomas in India, of Mark the Evangelist in Alexandria, etc.

5. Extent of the Expansion

Information about the apostolic activity of St. Paul is by far the most extensive, thanks to the accounts in the Acts of the Apostles and the important corpus of Pauline letters. St.Paul was the Apostle of the Gentiles, par excellence, and his missionary journeys brought the gospel to Asia Minor and Greece, where he founded and directed many churches. Taken prisoner in Jerusalem, his long captivity gave him an opportunity to bear witness to Christ before theSanhedrin, the Roman governors of Judea and KingAgrippa II. After being brought to Rome he was set free by Caesar’s courts and probably during this period made a missionary journey to Spain, which he had been planning for some time. Imprisoned for a second time, he was tried again and found guilty and died a martyr in the imperial city.

The work of the Apostles does not complete the picture of the spread of Christianity in the ancient world. For the most part, the bearers of the first tidings of the gospel must have been ordinary, humble people – civil servants, businessmen, soldiers and slaves. As a generalization, it may be said that during these early centuries Christianity was to be found more in the cities than among the rural communities. By the time the Church obtained its freedom, in the fourth century, Christianity was deeply rooted in many parts of the near east, such as Syria, Asia Minor and Armenia; and in the west, in Rome and its surrounding area and in Latin Africa. The gospel also had a considerable presence in the Nile valley and in various parts of Italy, Spain and Gaul.