1 Corinthians 9:16

Just because I preach the gospel. Being a teacher gives Paul no right to boast about it. The false teacher boasted very much about himself, so Paul makes a strong statement that he is Christ's slave (1 Corinthians 9:17; see note on 1 Corinthians 4:1; 1 Corinthians 4:6). And how terrible It would be! As an apostle, Paul is a "soldier under orders," and if he did not fulfill his mission, he would expect to be punished. [Some see in Philippians 3:12 Paul saying that he is an enemy taken captive, who must serve his captor. (1) Paul was trying his best to serve God when he met Jesus; (2) We are all enemies who have been taken captive and changed into friends of God.]