Opening Verse: Have mercy upon me, O God, according to thy lovingkindness: according unto the multitude of thy tender mercies blot out my transgressions. Wash me throughly from mine iniquity, and cleanse me from my sin. For I acknowledge my transgressions: and my sin is ever before me. Psalm 51:1-3, KJV. Psalm 51 was written after the prophet Nathan confronted David over his adultery with Bathsheba and the murder of Uriah. It is the most famous penitential psalm in Scripture, and it reveals what true repentance looks like in the heart of a man who belongs to God. David had tried to hide his sin. He had deceived, manipulated, and even killed to cover his tracks. But God was not mocked. He sent Nathan with a word that cut through every defense, and David broke. Exposition: David did not offer excuses. He did not minimize his sin. He did not appeal to his past faithfulness or his position as king. He cried out for mercy based entirely on God's character. Have mercy upon me, O God, according to thy lovingkindness. The ground of his hope was not his own sorrow, not his own resolve to do better, but the multitude of God's tender mercies. He asked God to blot out his transgressions, to wash him thoroughly, to cleanse him from his sin. These are not the prayers of a man who thinks he can fix himself. They are the prayers of a man who knows that only God can cleanse a defiled heart. Against thee, thee only, have I sinned, and done this evil in thy sight. David recognized that his sin was primarily an offense against the holiness of God. Bathsheba and Uriah were wronged, but the ultimate violation was against the Lord. Behold, I was shapen in iniquity; and in sin did my mother conceive me. David did not blame his circumstances, his passions, or his power as king. He traced his sin to its root: he was a sinner by nature, born in iniquity, inclined to evil from the womb. This is the Reformed doctrine of original sin in plain dress. Theological Insight: True repentance is not merely a human decision to turn from sin. It is a gift of grace, wrought in the heart by the Holy Spirit. The same God who convicts the sinner also grants the brokenness that leads to restoration. David prayed, Create in me a clean heart, O God; and renew a right spirit within me. Cast me not away from thy presence; and take not thy holy spirit from me. Restore unto me the joy of thy salvation; and uphold me with thy free spirit. Psalm 51:10-12, KJV. Notice the order. David asked God to create, to renew, to restore, to uphold. He did not say, I will create in myself a clean heart. He knew that repentance, like faith, is a divine work. God must grant it. The broken and contrite heart is itself a gift. The sacrifices of God are a broken spirit: a broken and a contrite heart, O God, thou wilt not despise. Psalm 51:17, KJV. The Reformed tradition teaches that repentance is both a grace and a duty. We are commanded to repent, yet we cannot repent apart from the enabling grace of the Spirit. When God grants repentance, He turns the heart, breaks the will, and restores the joy of salvation. This is why the gospel is called good news even for the chief of sinners. Application: First, when you sin, do you make excuses, minimize the offense, or blame others? Or do you confess, as David did, that your sin is against God alone? Second, do you understand that your repentance is not what earns God's forgiveness, but that your forgiveness was purchased by Christ and your repentance is the evidence that His grace is at work in you? Third, are you resting in the promise that God does not despise a broken and contrite heart, no matter how great your sin? Prayer Prompt: O God, I confess that I am a sinner by nature and by choice. My heart is deceitful and desperately wicked. I cannot cleanse myself. I cannot even repent rightly apart from Your Spirit's work. Create in me a clean heart, O God. Renew a right spirit within me. Restore to me the joy of Your salvation. Thank You that in Christ, my transgressions are blotted out, my iniquity is washed away, and my sin is cleansed by His precious blood. In Jesus' name, Amen.