Many biblical scholars find St. Mark the Evangelist mentioned in various places in the New Testament, highlighting his activity in the early Church.
St. Mark the Evangelist, writer of the Gospel of St. Mark, can be found in multiple places in the Bible. Though he is never mentioned in the gospels themselves, he does pop-up on occasion in the New Testament.
First of all, St. Mark is often identified with the “John Mark” in the Acts of the Apostles.
After Barnabas and Saul completed their relief mission, they returned to Jerusalem, taking with them John, who is called Mark.Acts 12:25
Secondly, St. Mark appears in St. Paul’s letters, such as this mention in his letter to Timothy.
Luke is the only one with me. Get Mark and bring him with you, for he is helpful to me in the ministry.2 Timothy 4:11
More importantly, St. Mark is believed to be the Mark mentioned by St. Peter in his letter.
The chosen one at Babylon sends you greeting, as does Mark, my son.1 Peter 5:13
The Catholic Encyclopedia explains how an early tradition places St. Mark as a disciple of St. Peter and that his Gospel was derived from his discussions with him.
When we turn to tradition, Papias (Eusebius, Church History III.39) asserts not later than A.D. 130, on the authority of an “elder,” that Mark had been the interpreter (hermeneutes) of Peter, and wrote down accurately, though not in order, the teaching of Peter.
Modern biblical scholars tend to disagree on the identity of Mark in the Bible, while early Church tradition combines all the appearances of “Mark” in the New Testament and connects them to the Gospel writer.
Even though St. Mark wasn’t numbered among the 12 apostles, he may have had a first-hand witness, St. Peter, to consult when he wrote his Gospel.