Psalm 69 is the song of a believer in pain and distress, crying out to God for rescue. He has been loyal to God and that loyalty has not resulted in any earthly blessing or prosperity. Indeed, he is suffering because of his faithfulness. In response to the mocking of the people, he calls for God to bring judgment.
There are numerous New Testament quotations from and allusions to this psalm (John 15:25; 2:17; Romans 15:13; Revelation 11:3; John 19:28; Romans 11:9-10; Acts 1:20; Luke 10:20). Inspired by the Spirit, the words of this song are the words of Jesus Christ. Led by him we sing these words, words that call for the judgment of those opposed to God’s King (Psalm 69:22-28). Paul called for such judgment in Galatians 1:8-9. We must also learn to do so, to view the gospel in the same light that he did.
6 I am astonished that you are so quickly deserting him who called you in the grace of Christ and are turning to a different gospel