What does Psalm 66:19 mean?

God listened to the psalmist's prayer and answered it (Psalm 66:13–15). He wants others to know about this. But the psalmist also strives for people to understand that personal sin will dampen this relationship (Psalm 66:18). When sin no longer lurks in the heart and the path is clear between the believer and God, answered prayer results. While God is not obligated, He does look favorably on those who have accepted Christ for salvation.

David provides an example of this truth. In Psalm 51 he describes the pain of broken fellowship with God. This happened because David committed adultery and arranged a murder (2 Samuel 12:7–11). He cries out to God for cleansing (Psalm 51:7), for forgiveness of sin (Psalm 51:9), and for a new, forgiven heart (Psalm 51:10). In Psalm 32 he expresses the joy of answered prayer. He describes the blessing of forgiveness (Psalm 32:1–2). He writes, "Blessed is the one whose transgression is forgiven, whose sin is covered. Blessed is the man against whom the LORD counts no iniquity, and in whose spirit there is no deceit." No sin is too great for the Lord to forgive when the sinning believer sincerely confesses it and asks God for forgiveness.

Here, the psalmist's prayers directed towards God aren't clouded by a heart of sin and wickedness.