Paul wrote most of his letters to churches. A few he wrote to pastors. And then there is the letter he wrote to his friend Philemon.

Paul loved Philemon. They were both eager to share the gospel. They both worshiped the Lord Jesus. Philemon brought Paul joy and comfort. Many believers were encouraged by Philemon.

Paul said all of that in his letter to Philemon. But there was something else he wanted to talk about. While Paul was in prison, he met a man named Onesimus. Paul told Onesimus the good news about Jesus, and Onesimus became a Christian. He was a changed man.

He was also a slave—Philemon’s runaway slave. Through most of human history, there have been slaves. Sometimes slavery was temporary, but it could also be permanent. Sometimes slaves were treated relatively well, but they could also be treated terribly.

We don’t know why Onesimus was a slave, or what kind of slave, or how Philemon treated him as a slave. What we do know is that Paul wanted Philemon to release Onesimus as a slave.

“I am an old man,” Paul wrote to Philemon. “I could command you to do the right thing, but I want you to come to that decision on your own. I met your servant Onesimus. You know his name means ‘useful.’ Well, he is more useful than ever before. I led him to the Lord, and now Onesimus is a Christian!”

Paul was sending Onesimus back, but he wanted Philemon to change, just like Onesimus had changed.

“Maybe this was God’s plan all along,” Paul said. “When you meet Onesimus again, he will be more than a slave. He will be your brother in Christ! So if we are still friends and partners in the gospel, I want you to receive Onesimus like you would receive me. And if he owes you anything, charge it to my account.”

Paul was certain Philemon would give Onesimus his freedom.

“I am confident of your obedience,” Paul wrote. “In fact, I know you will do even more than I can imagine for our brother Onesimus. I can’t wait to see you again, old friend. Keep praying for me, and I’ll get out of this prison and stay in your home very soon.”

It was a short letter Paul wrote to Philemon, but full of big things. In the days of the early church, there were lots of slaves in the Roman Empire. That was just the way things were. But Paul wanted everyone to know that wasn’t the way things should be.