17 From now on let no one cause me trouble, for I bear on my body the marks of Jesus.
18 The grace of our Lord Jesus Christ be with your spirit, brothers. Amen.
I find it interesting that Paul refers to the marks on his body, calling them the marks of Jesus. This, after he rebukes those in Galatia who thought the bodily mark of circumcision should be held in such high regard. But this is different on so many levels. Circumcision was a ritual mark that was for all men. Paul's marks were unique to him, a result of his calling.
When he calls them "the marks of Jesus," it is almost as though he was given those marks by Jesus Himself. While at first this sounds crazy, remember that the apostles also rejoiced for being counted as worthy to receive the beatings they were given as they left the ruling Jewish body. (Acts 5:40-42)
Paul closes by wishing them the grace of Jesus. It is grace that binds us, and Paul knew this. It is grace that changes us, and Paul knew that. It is grace that saves us, and Paul knew that too.