What does Philemon 1:24 mean?

Paul mentioned one of his companions in verse 23: Epaphras. Here, he refers to four others: Mark, Aristarchus, Demas, and Luke. These men were not imprisoned like Paul and Epaphras, but were in Rome to help Paul with his ministry.

The "Mark" mentioned here is John Mark, a Christian related to Barnabas. The early church met in his mother's home in Jerusalem (Acts 12). Mark later joined Paul and Barnabas but left during the trip. Paul and Barnabas later parted ways because Paul did not want to take Mark on another mission trip. Barnabas and Mark instead left for Cyprus. Mark was also mentioned in Colossians 4:10 and is also seen with Peter in 1 Peter 5:13 (likely in Rome) and 2 Timothy 4:11 (somewhere outside of Rome). At that point, Paul and Mark had reconciled and served together again.

Aristarchus had traveled with Paul in the past (Acts 19:29; Acts 20:4) and was mentioned as a fellow prisoner with Paul in Rome in Colossians 4:10.

Demas was also mentioned alongside Luke in Colossians 4:14. Unfortunately, according to 2 Timothy 4:10, he later abandoned Paul.

Luke is the author of the book of Acts and the Gospel of Luke. He worked as a missionary with Paul, and was with him in Rome during his imprisonment. It is significant that Mark and Luke were together during this time. Both of their gospels were likely written close to this time, with both writers in Rome. This suggests a date for both gospels prior to the first half of the AD 60s.