17 Therefore I have reason to glory in Christ Jesus in the things which pertain to God.
In verses 14 to 21 Paul spoke of his past ministry to the Gentiles.
“Therefore” expresses the result of Paul’s ministry to the Gentiles.
I have reason to glory [boast] in Christ Jesus
Paul boasted about the work of Christ, not about his achievements. Everything that Paul accomplished was accomplished in the strength of Christ.
in the things which pertain to God.
The boast is what God did on Paul’s behalf. The “things” is God’s converting work among the Gentiles.
Our only basis for bragging in the work of God is what Christ has done.
There is an area where the Christian may glory. We glory in the work of God through our ministries. This is a proper pride. Sinful pride is what glories in self.
1 Co 1:31, that, as it is written, “He who glories, let him glory in the Lord.”
A person has no right to take credit for what someone else achieves. We have no right to take credit for what Christ has done.
Ga 6:14, But God forbid that I should boast except in the cross of our Lord Jesus Christ, by whom the world has been crucified to me, and I to the world.