Mark was sometimes called by his Jewish name, John, and sometimes by his Roman name, Mark.
Mark was someone who failed but managed to recover from his failure to finish well. When Barnabas and Paul went as missionaries, they took Mark to help.
(Acts 13:5 NIV) When they arrived at Salamis, they proclaimed the word of God in the Jewish synagogues. John (i.e. Mark) was with them as their helper.
They went from Antioch to Cyprus and then on to Pamphylia, where Mark left them and returned to Jerusalem. The most likely reason was because of the dangers of the rough interior country towards which Paul was heading. Apparently Mark’s zeal had dwindled and his courage had failed him.
(Acts 13:13 NIV) From Paphos, Paul and his companions sailed to Perga in Pamphylia, where John (i.e. Mark) left them to return to Jerusalem.
Later, when Paul and Barnabas planned another journey, Barnabas wanted to take Mark. When Paul refused, Barnabas and Mark went together while Paul and Silas went together (Acts 15:36-40).
However, Mark did not allow himself to remain in failure. He proved himself once again to be a faithful servant of God. He later rejoined Paul in his ministry. We know this because when Paul wrote to Philemon, Mark was one of Paul’s fellow workers who sent greetings (Philem. 24). Paul wrote to the Colossians to receive Mark if he came to them (Col. 4:10). When Paul wrote his final letter to Timothy, he asked Timothy to bring Mark with him because Paul considered Mark a useful helper (2 Tim. 4:11). Mark moved from being someone disapproved by Paul to one of the three men that Paul wanted to be with him in the end.
Mark was not only useful to the great apostle Paul; he was useful to the leader of the church Peter, who referred to Mark as his “son,” and sent greetings from him near the end of his first letter (1 Pet. 5:13). Mark had come to the point where he was worthy to have his encouragement and prayers sent along with Peter’s to strengthen the persecuted disciples of Christ.