What does Acts 13:13 mean?

After Barnabas and Saul were commissioned by the Holy Spirit and the leaders of the church in Syrian Antioch, they sailed west to Barnabas' homeland of Cyprus (Acts 13:1–4). There, they preached in Jewish synagogues and brought a Roman proconsul to a saving faith in Jesus—much to the dismay of a Jewish false prophet who had apparently been using him (Acts 13:5–12). During that time, Saul took on the Roman name Paul and became the dominant teacher. The group becomes "Paul and his companions" or "Paul and Barnabas" (Acts 13:46) and only reverts when they are mistaken for Greek gods (Acts 14:14) or are among the leaders of the church in Jerusalem (Acts 15:12, 25).

Paphos is the port town on the southwest coast of Cyprus. The book of Acts does not record Paul returning to Cyprus, although Barnabas and John Mark do (Acts 15:39). Pamphylia and Pisidia (see Acts 13:14) are two small districts with unstable borders. Sometimes they are independent while at other times larger, stronger districts annex them.

John Mark is Barnabas' relative (Colossians 4:10), not the apostle John (Mark 1:19–20) or John the Baptist. He is the author of the gospel of Mark, the son of Mary who owns a house in Jerusalem (Acts 12:12), and possibly the young man who escaped the guards who arrested Jesus (Mark 14:51–52).

We are not told why John Mark leaves Paul and Barnabas, but it causes the two problems in the future. When Paul and Barnabas prepare to leave on their second missionary trip, Paul will refuse to allow John Mark to join them. Paul and Barnabas cannot come to an agreement, so Barnabas takes John Mark back to Cyprus and Paul takes Silas (Acts 15:36–41). Later, Paul and John Mark will reconcile; Paul will call him a "fellow worker" and tell Timothy that he is "useful" for ministry (Philemon 1:24; 2 Timothy 4:11).