What does the Bible say about true repentance?

True repentance is portrayed in Psalm 51 as a deep and sincere acknowledgment of sin against God. David, the author, expresses this profound sense of need for God's mercy and forgiveness, recognizing his failures and sinful nature. Authentic repentance is not merely an external display or acknowledgment of wrongdoing; instead, it comes from a heart that understands the gravity of sin and cries out for God's cleansing. As David states, 'Purify me with hyssop, and I shall be clean; wash me, and I shall be whiter than snow' (Psalm 51:7). This highlights that one's repentance must be directed towards God, acknowledging that all sin is ultimately against Him, as David confesses: 'Against You, You only, have I sinned and done what is evil in Your sight' (Psalm 51:4).