“Barnabas agreed and wanted to take along John Mark. But Paul disagreed strongly, since John Mark had deserted them in Pamphylia and had not continued with them in their work” (Acts 15:37-38 NLT).

THE DISAGREEMENT OVER JOHN MARK
Paul wanted to travel to check on the new believers that had come to faith on their first missionary journey. Barnabas agreed. However, they disagreed on taking John Mark with them again. Apparently, Paul considered the young man unreliable after he had “deserted them” and went home early on their last trip. But Barnabas, being the encourager that he was, wanted to give John Mark a second chance. Just as Barnabas had seen the potential in Paul, he saw it in John Mark. This led to a sharp disagreement, so they ended up splitting up the power team. Barnabas began to travel with John Mark. And Paul took on Silas as his new missionary companion.
 
Even committed believers can have disagreements. In this case, it led to two missionary teams going out. Over time, apparently the disagreement was forgiven and forgotten. For Paul wrote in at least two places concerning John Mark. In his letter to the church at Colossae, he wrote, “Aristarchus, who is in prison with me, sends you his greetings, and so does Mark, Barnabas’s cousin. As you were instructed before, make Mark welcome if he comes your way” (Col. 4:10). When others had deserted Paul while he was in prison, John Mark had remained faithful to him.
 
And in Paul’s second letter to Timothy, he wrote, “Bring Mark with you when you come, for he will be helpful to me in my ministry” (2 Tim. 4:11). Paul’s impression of John Mark had certainly changed.
 
Traditionally, John Mark or simply “Mark,” is considered the author of the gospel according to Mark. I’m glad Barnabas kept on believing in John Mark, and Paul too, for that matter!