Have mercy on me, O God, according to your unfailing love; according to your great compassion blot out my transgressions. Wash away all my iniquity and cleanse me from my sin. For I know my transgressions, and my sin is always before me. Against you, you only, have I sinned and done what is evil in your sight; so you are right in your verdict and justified when you judge. Surely I was sinful at birth, sinful from the time my mother conceived me. Yet you desired faithfulness even in the womb; you taught me wisdom in that secret place. Cleanse me with hyssop, and I will be clean; wash me, and I will be whiter than snow. Let me hear joy and gladness; let the bones you have crushed rejoice. Hide your face from my sins and blot out all my iniquity. Create in me a pure heart, O God, and renew a steadfast spirit within me. Do not cast me from your presence or take your Holy Spirit from me. Restore to me the joy of your salvation and grant me a willing spirit, to sustain me. Then I will teach transgressors your ways, so that sinners will turn back to you.
Psalms 51:1-13 NIV