What does Romans 15:17 mean?

Paul has just described his work in writing God's Word to the Roman Christians. In a way, he has said, he is like a priest of the gospel of God and they are like the offering he presents to God. His desire is to see the Holy Spirit sanctify their lives in a way that will make them acceptable offerings on Paul's behalf.

Paul is not suggesting that he should be given personal credit for the lives of service to God that may come from these or other Christians. Instead, he is boldly pointing to them as the product of his effort in the power of Christ. He insists here that the fruit that comes from their lives gives him reason to be proud of the work that he has done for God and in Christ Jesus.

This is not selfish or sinful boasting about his own accomplishments. As Paul will clarify to a point in the following verse, he is proud to have been used by God to accomplish God's purposes in God's power.