What does Acts 15:37 mean?

Paul has proposed a second missionary trip with Barnabas to revisit the churches they planted in central modern-day Asia Minor. In that first trip, they started with Barnabas' young cousin, John Mark. Mark, however, left them in Perga, near the beginning of their trip (Acts 13:13). We aren't told why Mark left. He was deeply involved in the church in Jerusalem, as his mother owned the house where some of the leaders met (Acts 12:12); some scholars think she hosted the Last Supper (Mark 14:14–15). Mark also wrote the gospel that bears his name, probably on behalf of Peter.

It shouldn't be a surprise that Barnabas would want to give Mark a second chance. His real name was Joseph, but the apostles gave him the nickname "Barnabas" which means "son of encouragement" (Acts 4:36). When Paul, the persecutor of the church, returned to Jerusalem after coming to faith in Jesus, the disciples refused to see him. Only Barnabas was willing to risk his life and meet to determine if Paul had really changed (Acts 9:26–27). And when the church in Jerusalem heard that Jewish Christians from Cyprus and Cyrene had shared Jesus' offer of forgiveness to Gentiles in Syrian Antioch, they sent Barnabas to see if their faith was sound. Barnabas found a thriving new church in need of teaching and leadership. He made the bold move of finding Paul in nearby Tarsus and inviting him to help disciple the new believers (Acts 11:19–26).

The disagreement may have involved a measure of hurt feelings. This is unfortunate, but God can redeem any situation. Paul brings Silas, also a Roman citizen, into what will prove to be a difficult trip. And Barnabas provides Mark with a chance for redemption. Later, in his letters, Paul will speak fondly of the young man he once rejected (Colossians 4:10; Philemon 1:24; 2 Timothy 4:11). Many commentors note that both sides of this debate had merit, so the end solution was likely the best possible approach.