What does Philippians 2:22 mean?

The Philippians already knew about Timothy and his reputation. Some translations specify his name here, for clarity, though the original Greek literally says "his." Timothy's relationship with Paul was compared to a son with a father. Timothy was both a coworker and spiritual family member with Paul. Given the type of assignments Paul gives Timothy in the Bible, his level of trust must have been extremely high. It would not be a stretch to refer to Timothy as Paul's "right hand man."

Interestingly, Paul compares the father-son dynamic to Timothy's service with him in the gospel. In other words, here the description is of Timothy's service with Paul rather than his relationship. This connection would have made much greater impact during the time Paul wrote. Then, most sons served in the same vocation as their father from a young age. Timothy and Paul had worked together like father and son for some time. They were close relationally as well as in their common work to share the good news with others.