What was the relationship between Luke and Paul?
Paul calls Luke “the beloved physician.” When Paul was in prison, Luke was the only one with him. Colossians 4:14; 2 Timothy 4:11
What the Bible says
Colossians 4:14
Luke, the most dear physician, saluteth you: and Demas.
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.