St. Mark was an evangelist, or Gospel writer. In fact, he was the pioneer in Gospel writing. His is the shortest and the oldest of the Gospels. Little is known of Mark except from the New Testament. He was not one of the twelve apostles, but was a member of the first Christian community. Mark had firsthand experience of the early Church and apostolic life. He was a traveling companion and assistant of Paul and Barnabas on the first missionary journey. Something happened to Mark on that journey, perhaps homesickness, so he returned to Jerusalem. The incident caused a quarrel between Paul and Barnabas. Barnabas, Mark's cousin, was sympathetic toward Mark, but Paul would not hear of Mark accompanying them again. Later Paul and Mark must have been reconciled, because when Paul wrote to Timothy during his final imprisonment, he asked for Mark's help.