The most important message of Psalms is that part of being mortal is making mistakes. Good people are willing to learn from their mistakes, do penitence, and then move on. In fact, Psalm 90:3 indicates that God says: “Return, children of man.” God wants the sinner to return to him by repenting of his wicked ways. Psalm 51 also teaches us that the door to penitence is always open as long as a person acknowledges his or her misdeeds. This psalm refers to the story of David’s adultery with Bathsheba which is described in II Samuel 12-13.
For the director of music, A Psalm of David. When Nathan the prophet came to him after David had committed adultery with Bathsheba. Have mercy on me, O God, according to Your lovingkindness; according to your vast compassion blot out my transgressions. Wash away all my iniquity and from my sin purify me. For I know of my transgressions, and my sin is before me always. Against You alone have I sinned, and done that which is evil in Your eyes; therefore, you are proved right when you speak and justified when you judge... Hide Your face from my sins, and all my iniquities blot out. A pure heart create for me, God; and a spirit of correctness renew within me. Cast me not away from Your Presence, and take not Your Holy Spirit from me (Psalm 51:1-6; 11-13).