What does 1 Corinthians 9:19 mean?

Freedom and slavery were key ideas for Paul. The contrast between servants and masters in the ancient world was much more pronounced than the divide between rich and poor, or between owner and employee, as seen in modern culture. These ideas describe how Paul viewed himself in relation to God, to the law of Moses, and to other people. He has written of himself in the previous verses as a trusted "slave" of Christ, under orders to preach the gospel message. He carries out that duty because he must. Like the Old Testament prophets, he sees himself as having no choice in the matter.

He believes himself to be free, on the other hand, when it comes to those he serves. This was true both legally and spiritually. As a Roman citizen, Paul was truly free and not a bonded servant or slave. He enjoyed the rights owed to every true citizen of Rome. In addition, he had been freed from responsibility to the law of Moses by his faith in Christ. He owed nothing to the Jewish religious leaders.

And yet Paul now says that he has voluntarily declared himself a servant / slave of all people. In other words, he believes that his mission to reach people with the gospel of Jesus includes placing himself under the authority of everyone, in a sense. The following verses elaborate on what he means by this.