Being certain of your own goodness.
David provides a picture of a truly good man that God will vindicate. It will be someone who is blameless, leading a life of unfaltering trust in God. Blamelessness is mindfullness and dependence on God’s character of unfailing love and trustworthiness. So rarely can you catch the psalmists bragging to God about their goodness… when you really look at it, they are calling God to act on his promise of grace. The form is of self justification, the substance winds up being a bold claim on justification by faith.
Then he lists some specific negatives and positives of his goodness: not being one of the hypocrites, evildoers, deceivers or wicked. Instead he washes his hands in innocence, praises God and proclaims gods wonderful deeds, and loves the place where god’s glory dwells. The nature of being a good man is acknowledgement of God. Maybe the deceptions and hypocricies of the wicked are in essence a refusal to acknowledge God?
Still it hard not to think “no you haven’t” when David says he has led a blameless life. In Psalm 51 he will deliver a painful plea for deliverance from his own sin. We know of his huge sins from the histories of his life, the bible makes no secret of it.
He has that arrogance that Christians are often accused of, the certainty of forgiveness. Great final image, the King stands on level ground, praising God along right in the middle of “the great congregation”. His specialness is his relationship with God: God’s glory, not his own elevation.