Much of what we know about St. Mark, the author of the Second Gospel, comes largely from the New Testament and early Christian traditions. Mark the Evangelist is believed to be the ‘John Mark’ referred to in the Acts of the Apostles, the history of the early Church found in the Canon of the New Testament.
He was the son of Mary of Jerusalem (Acts 12:12) whose home became a meeting place for the apostles. He is also the cousin of St. Barnabas (Colossians 4:10), a Levite and a Cypriot.
Mark joined St. Paul and St. Barnabas on their first missionary journey to Antioch in 44 A.D. When the group reached Cyprus, Christian tradition holds that Mark left them and returned to Jerusalem, possibly because he was missing his home (Acts 13:13). This incident may have caused Paul to question whether Mark could be a reliable missionary. This created a disagreement between Paul and Barnabas and led Paul to refuse Mark’s accompaniment on their second journey to the churches of Cilicia and the rest of Asia Minor.
However, it can be assumed the troubles between Paul and Mark did not last long, because when Paul was first imprisoned, Mark, who was at the time in Rome with plans of visiting Asia Minor, visited him as one of his trusted companions (Col 4:10).