Fearing punishment for an offense against his master, Onesimus fled to Rome, but he was imprisoned for being a runaway slave. In prison he came across the [[Apostle Paul]] and was enlightened by him, and was [[baptize]]d. St. Paul was personally acquainted with Philemon, and wrote him a [[Book of Philemon|letter]] filled with love, asking him to forgive the runaway slave and to accept him like a brother. He sent Onesimus with this letter.
After St. Philemon received the letter, he not only forgave Onesimus, but also sent him back to Apostle Paul in Rome. Afterwards, Philemon was consecrated [[bishop]] of the city of Gaza .
After the death of the Apostle Paul, St. Onesimus served the apostles until their end, and he was made a bishop. After the death of the holy apostles he preached the [[Gospel]] in many lands and cities of Spain, Carpetania, Colossae, and Patras. In his old age, Onesimus occupied the bishop's throne at Ephesus, after the [[Apostle Timothy]]. When they took St. [[Ignatius of Antioch|Ignatius the God-Bearer]] to Rome for execution, Bishop Onesimus came to meet with him with other Christians, as St Ignatius mentions in his [[Epistle to the Ephesians]].