You could be forgiven for assuming that as soon as Saul the persecutor became Paul the disciple, he at once set out on his travels to preach the gospel. A close inspection of his letters shows this was not so. It was to be many years from his dramatic conversion before the great apostle began those famous journeys which take up so much of the Acts of the Apostles. In fact, the whole process of expanding the scope of the gospel call went ahead surprisingly slowly. Although Jesus had commanded the twelve apostles to "go into all the world and preach the gospel" (Mark 16:15), they had an instinctive bias towards the Jews as the chosen people, and it took them a long time to get used to the idea that God now favoured the call of Gentiles (non-Jews) into the gospel net.
The work received an impetus from two prominent disciples, Philip and Peter. Philip was probably a foreign born Jew. His name is Greek, and he was one of a handful of trustworthy men chosen by the Jerusalem church to supervise the distribution of alms money to the widows of overseas Jews. This background would make him less hostile to foreigners than a home-born Jew. Travelling north from Jerusalem, Philip commenced a one–man campaign to bring the news of Jesus to the Samaritans. These were the descendants of a group of foreigners deported to Israel over 500 years before by the Assyrians. In that time they had picked up the worship of Israel's God and obeyed the Law of Moses, but because they were not demonstrably descended from Abraham they were despised by the Jews and barred from the Temple at Jerusalem. Jesus spent two days among them at the beginning of his ministry, but later found them hostile towards him (John 3:40, Luke 9:52, 53). Coming to this maligned and hated minority, Philip set to work and "proclaimed to them the Christ" (Acts 8:5). He told them about the Kingdom of God that Jesus is going to bring, and taught them to call him Christ, which means 'anointed' or king. The reaction was marked. "There was much joy in that city" is the comment in Acts 8:8. "When they believed Philip as he preached good news about the Kingdom of God and the name of Jesus Christ, they were baptised, both men and women" (Acts 8:12). Like the Jews on the Day of Pentecost, they were thrilled to find that God's love extended to them too, and their past sins could be washed away in the blood of the risen Jesus.
News of the developments in Samaria soon filtered through to the Apostles in Jerusalem. They immediately sent off Peter and John to find out what was going on. Perhaps they had reservations about whether it was right to preach to Samaritans. Peter and John, as leaders, must have felt particularly concerned that young Philip had set off without their official support. Whatever their feelings, they could not help but be impressed with the results of his labours, and soon threw themselves solidly behind the brave pioneer. They too "testified and spoke the word of the Lord … preaching the gospel to many villages of the Samaritans" (Acts 8:25).
An interesting point, in passing, is that when Peter and John joined Philip they were able to pass on the gift of the Holy Spirit to the newly baptised believers. They did this, after prayer, by the laying on of their hands (Acts 8:15, 17). This is important, because some evangelical groups today claim the Holy Spirit is given automatically to all believers, either before or after they are baptised. In the case of the first century Samaritans, the gift had not come by itself to the new disciples, neither was Philip empowered to pass it on. Only the two apostles had the authority that was required.
After Samaria, Philip continued to break fresh grounds. Commanded by the Holy Spirit to journey south, he was waiting beside the main road going down from Jerusalem to Egypt when a chariot came by containing an important looking coloured gentleman who, by coincidence, was reading the Bible as he jogged along. Here was Philip's opportunity. The Ethiopian had just completed the pilgrimage of a lifetime, travelling all the way from Africa to visit the magnificent Temple in the Holy City.