Have mercy on me, O God, according to your steadfast love;
according to your abundant mercy blot out my transgressions.
Wash me thoroughly from my iniquity, and cleanse me from my sin!
How aware of your sin are you? I find it’s often easy to minimize or brush under the carpet. Especially if it’s something others don’t know about, it can be easy to hide that aspect of my life, to pretend it doesn’t exist. But over time I start fooling myself, too, and I start to think that that part of my life isn’t so significant.
Whatever his attitude may have been beforehand, King David was made very much aware of his sin by the prophet Nathan (this psalm’s superscription says “when Nathan the prophet went to him, after he had gone in to Bathsheba”). Despite his pretty good track record up to this point, David’s adultery and conspiracy to murder are now known not only to himself and those intimately involved, but to others.
And, of course, to God.
So David calls on God to have mercy on him. He recognizes his own transgression (an act of criminal rebellion); he knows he needs purification from his iniquity (his wrong-doing, his guilt); his sin (missing the mark) must be cleansed. In no uncertain terms, David has acted in rebellion against God (cf. v. 4).
No doubt David realises that he has no option but to call on God’s mercy. Sin required sacrifice, but for the kind of deliberate sinfulness this king of Israel has taken part in there was no sacrificial possibility, only death as a just punishment (cf. Lev 20:10; Num 35:31‑32). David, knowing his actions and his condition before God, has no option but to pray to God for clemency.
So he calls on God’s steadfast love. This is something God has consistently shown towards his people. His faithful love is part of his revealed character. When the Lord passed in front of Moses in Exodus 34 he said this:
The Lord, the Lord, a God merciful and gracious, slow to anger, and abounding in steadfast love and faithfulness, keeping steadfast love for thousands, forgiving iniquity and transgression and sin, but who will by no means clear the guilty, visiting the iniquity of the fathers on the children and the children’s children, to the third and the fourth generation. (Exod 34:6‑7)
This ‘steadfast love’ for thousands is the same love that David seeks mercy in. He knows God’s willingness to deliver on his promises, his loyal commitment to his people. His God is a God of justice, who is right in his judgements (cf. Ps 51:4), who will not arbitrarily declare the guilty innocent—yet is still merciful, gracious, compassionate, and fiercely, faithfully, steadfastly loving.
We need to realise, however, that David isn’t simply seeking a pardon so that he can carry on as before. He asks not only for mercy, but for transformation: “Create in me a clean heart, O God, and renew a right spirit within me” (v. 10). We all, like David, are in need of a new heart, a new attitude committed not to ourselves and our own interests but to God and his righteousness. David wants to taste the joy of salvation, to be glad, to sing about his deliverance. He wants to be changed to live rightly, to be capable of resisting sin, to be wise and upright.
How does that new heart David longs for come about? What would David have been envisioning when he asked God to do that? By just about any account David is a great man, a successful king… yet still a sinner. He is one who looks forward to another king, another messiah. David’s need of transformation points us to the transformation we all require, a new life, doing away with the old rebellious self forever. David’s confession points us to the compelling love of Christ.
Confession of sin is right. Like David, we’re rebellious creatures to the core. We may not be adulterous murderers—at least not in the way that David was—but our sin is still ever before us. We are guilty, in need of God’s forgiveness. Like David, we by nature are sinful from birth, in need of mercy, needing to be cleansed from our sin to have a right standing before God. In the end, of course, it was a sacrifice that cleansed David and cleanses us: the blood of Jesus (1 John 1:7). John’s comforting word to us is that if we confess our sins, God is indeed faithful and just, and will cleanse us from all unrighteousness.
Thanks be to God that he has had mercy on us, that according to the steadfast love he has shown in Christ’s death for all he has cleansed us and given us new life!
Note: I am grateful for the chapters on Psalm 51 in Ray Galea’s reflections on the Psalms in God is Enough (available from Matthias Media). Some of my reflections have been informed by his work.