An understanding of the New Testament letters of Paul ("St. Paul", "Paul the apostle") requires a summary of the travels that Paul took over about a dozen years (from 46-58 CE?) These journeys are described in chapters 13-21 of the book of Acts and represent the very earliest history of the Christian church.
The missionary journeys of Paul
According to Acts 13, the Holy Spirit tells the church in Antioch to "set apart Barnabas and Saul for the ministry I have planned for them." And so this early church ordains two missionaries and sends them off, first to the island of Cyprus, and then on to Asia Minor (now Turkey) to tell the Jewish people in those locations about their recently revealed Messiah. The book of Acts eventually describes three missionary journey and ends with a fourth journey, a forced journey in which Paul, as prisoner, travels to Rome.It is on one of those missionary journeys that the author of Acts, Luke, becomes a convert and travels with Paul.
The first missionary journey
In this first journey, described in Acts chapters 13 & 14, Barnabas is the presumed leader; he has been a disciple much longer than Saul and is more experienced. But Saul is the "talker" and seems to draw much of the attention.The first missionary journey (Acts 13:4-14:28, about CE 46-48) begins with Paul and Barnabas visiting the island of Cyprus. They then visit southern Galatia (Perga, Pisidian Antioch) where they stay awhile before going on to Iconium. After conflict in Iconium, Paul and friends flee to Lystra and Derbe (and the surrounding region of Lycaonia, south of the province of Galatia.) In Lystra, after they heal a lame man, Barnabas is identified by the people as Zeus and Paul is called Hermes (Acts 14:11-13)
The map below (taken from Gracepoint notes, which took them, in turn, from the Holman Bible Atlas) displays Paul's first missionary journey.
Interlude
In Acts 15 we see the important meeting in Jerusalem, in which an official decision is made regarding Gentile Christians. This meeting is stimulated by the great success in the first missionary journey and by the obvious openness of the Gentiles (non Jews) to the message about Jesus the Messiah.The second missionary journey
The second missionary journey is reported in Acts 15:40-18:23 (49-52 CE?) It is possible that Paul visited north Galatia (administrative Galatia) at this time. This second journey is caused by a desire of Paul and Barnabas to revisit the synagogues and converts from the first journey. But at the very beginning, Barnabas wants to take John Mark and Paul does not, so the dynamic missionary duo split up, Barnabas with John Mark heading back to Cyprus while Paul take Silas and travels north through Syria into Asia Minor. In Lystra, a young disciple named Timothy joins Paul. Since Timothy is uncircumcised (his father is Gentile), to please the Jews in the area, Paul has Timothy circumcised.
The transition from third person to first person in Acts 16:11 most likely means that Luke, the author of the book of Acts, joins Paul at Troas and then for a time can tell the story in first person.
In Philippi after speaking in a small synagogue and baptizing new believer, Lydia, Paul and Silas are then thrown in prison. During the night an earthquake opens the prison doors and Paul and Silas are freed and their jailer becomes a believer. Paul frightens the local authorities by explaining that he is a Roman citizen. From Philippi the two travel on to Thessalonica where, as is their practice, they speak in the local synagogue. On to Berea and Athens, where Paul speaks at Mars Hill, to both open ears and skeptics. Luke lists by name several converts but also points out the Greek skepticism of someone claiming that a man was resurrected.
In Corinth, Paul meets a Jewish couple, Aquila and Priscilla, who, as believers, join Paul's ministry team. Silas and Timothy join Paul in Corinth but due to strong opposition from Jewish leaders, Paul leaves the synagogue and begins to speak and minister from the house of Titius Justus, presumably a Gentile. Luke records that a number of Jewish believers, including the synagogue leader, join Paul.
The third missionary journey
The third missionary journey (CE 53-58?) begins in Act 18:23, after the conclusion of the second journey and after "some time" at Antioch. In the third journey, Paul again returns to visit the various churches across Asia Minor. Galatia is explicitly mentioned in that verse, with Asia Minor presumably mentioned in two parts, as "Galatia and Phrygia."
Paul visits Ephesus (on the western coast of Asia Minor) in Acts 19 and there many followers of the goddess Artemus turn to the Jewish Messiah, to the point that those making money off of Artemis are infuriated and cause a riot. After that, Paul moves west across the Aegean to Macedonia and Greece, ministering in the places he had been before, including Philippi. Eventually he returns east to Troas (where he had picked up Luke) and there we have the story of Paul preaching very long (possibly all day) and a young man (with whom I have considerable sympathy) falling asleep during Paul's message. Young Eutychus pitches out a second story window and is picked up below as dead, but Paul's stretches over him, prays and revives him.
Paul visits Ephesus (on the western coast of Asia Minor) in Acts 19 and there many followers of the goddess Artemus turn to the Jewish Messiah, to the point that those making money off of Artemis are infuriated and cause a riot. After that, Paul moves west across the Aegean to Macedonia and Greece, ministering in the places he had been before, including Philippi. Eventually he returns east to Troas (where he had picked up Luke) and there we have the story of Paul preaching very long (possibly all day) and a young man (with whom I have considerable sympathy) falling asleep during Paul's message. Young Eutychus pitches out a second story window and is picked up below as dead, but Paul's stretches over him, prays and revives him.
Paul continues on to Miletus, near Ephesus, where a prophet warns that if Paul continues, as planned, to Jerusalem, he will end up in chains. But Paul must go .... The last half of chapter 20 of Acts is a moving goodbye from Paul, given to the elders from Ephesus, expressing his care and concerns for them.
From Miletus, Paul's entourage move on past Cyprus to Syria and then down to Caesarea. In Caesarea Paul is warned (a third time!) of the chains that wait for him in his Jerusalem trip. In this case, the warning is acted out; a prophet named Agabus takes Paul's belt and then ties up his own hands and feet to show what will happen "to the owner of this belt."
But Paul must go on, and the third missionary journey ends in Jerusalem with Paul's arrest there, at the end of Acts 21.
From Miletus, Paul's entourage move on past Cyprus to Syria and then down to Caesarea. In Caesarea Paul is warned (a third time!) of the chains that wait for him in his Jerusalem trip. In this case, the warning is acted out; a prophet named Agabus takes Paul's belt and then ties up his own hands and feet to show what will happen "to the owner of this belt."
But Paul must go on, and the third missionary journey ends in Jerusalem with Paul's arrest there, at the end of Acts 21.
Some resources and notes
Wikipedia, of course, has some good stuff. Check out the article on St. Paul.
The Christian Classic Ethereal Library, based at Calvin College, Grand Rapids, MI, has lots of excellent resources.
There is a summary of the missionary journeys from a webpage sponsored by Gracepoint church in Berkeley CA. The maps I used are taken from the Gracepoint notes, which took them, in turn, from the Holman Bible Atlas.