What was the relationship between Mark and Paul?
Mark left Paul in the middle of the first journey, and Paul did not want to take him along later. Years afterward, Mark was with Paul and was helpful to him. Acts 13:13; Acts 15:37-38; Colossians 4:10; 2 Timothy 4:11
What the Bible says
Acts 13:13
Now when Paul and they that were with him had sailed from Paphos, they came to Perge in Pamphylia. And John departing from them, returned to Jerusalem.
2 Timothy 4:11
Only Luke is with me. Take Mark, and bring him with thee: for he is profitable to me for the ministry.
Douay-Rheims Bible (Challoner revision), public domain.