Paul, a prisoner of Christ Jesus, and Timothy our brother, To Philemon our dear friend and co-worker.
Paul´s letter to Philemon is his shortest letter in the New Testament with only 385 Greek words. The word count may differ in other translations because of the limitation of corresponding vocabulary. The introduction indicates that the apostle was in prison and it is mostly likely the imprisonment described in Acts 28:30-31. This will mean that he was imprisoned in Rome. However, few scholars thought he was still imprisoned at Ephesus. Regardless of different views on the location of the prison, scholars are all in agreement that he was imprisoned when he wrote this letter to Philemon
Paul is not worried about the physical imprisonment because he does not describe himself as the prisoner of Romans but of Christ. His focus is on why he is in prison and this is the title he is proud of. He is not regretting being a prisoner of the gospel. The issue is not about being imprisoned but the reason why you are imprisoned. Being is prison for standing for what is ethically right is something to be proud of than being in prison for committing a crime. Nelson Mandela was imprisoned for nearly 30 years but he came out a saint and a model of people who lived a selfless life. Everyone is a potential candidate for a prison whether for right or wrong reasons. As Christians, we must not be afraid of being prisoners of the gospel.