It’s interesting that David says, “Against you and you only have I sinned” (v. 4). Um, didn’t David sin against Bathsheba, Uriah, Joab, his people? Certainly, but the root of all that sin was a heart that trusted in itself instead of in God, a lack of thanks which led to disobedience which led to not calling on God.
He asks God to create a clean heart in him. What new heart does David need? A heart of thanks, a heart that esteems God as God, God as the King and shepherd of his life. This heart cannot be achieved through going through the religious motions. Psalm 51:16-17 says that God doesn’t delight in the sacrifices and burnt offerings that are divorced from a heart yielded to God and thankful to Him.
As I read these Psalms over the course of a day last week, the dots began to connect for me. Trust in myself leads me to exchange shepherds (Psalm 49). I can still go through religious motions, still look like my life is OK, but inside my heart’s orientation has been changed from one of thankful dependence to one of self-righteous independence (Psalm 50). Obedience divorced from thankfulness leads to anger and entitlement. It leads to jealousy over what others have that you deserve, and you begin to think about how you might make that happen for yourself (Psalm 51). A thankful heart honors God, places Him in His rightful place on the throne of our life. And the proper response to the realization of our sin is repentance and asking for the mercy of God to reorient our heart.