For I acknowledge my transgressions

This is how a man should approach God after committing sin against God. David shows an example of humility, remorse and repentance as he approached God after being rebuked by his prophet. David opens up to God and declares his wrongdoing. His sin of adultery, he admits, is "Against You, You only, have I sinned," an act against God.

After his confession, David asks God to cleanse him, to give him a clean heart. The thing that concerns David is not being in God's presence and the Holy Spirit taken away from him - and he asks God for assurance in these. He asks God to restore him and even pledges to teach others against sinning.

David knows God well enough of His mercies, salvation and righteousness. Perhaps another person would have turned and hide from God, but David holds on to God even more desperately. David may have understood more than many religious leaders when he said that God is not pleased by burnt offerings and ritual sacrifices; instead God would be more pleased with a broken spirit and a contrite heart.

Psalm 51
To the Chief Musician. A Psalm of David when Nathan the prophet went to him, after he had gone in to Bathsheba.

 1 Have mercy upon me, O God,
         According to Your lovingkindness;
         According to the multitude of Your tender mercies,
         Blot out my transgressions.
 2 Wash me thoroughly from my iniquity,
         And cleanse me from my sin.
        
 3 For I acknowledge my transgressions,
         And my sin is always before me.
 4 Against You, You only, have I sinned,
         And done this evil in Your sight—
         That You may be found just when You speak,[a]
         And blameless when You judge.
        
 5 Behold, I was brought forth in iniquity,
         And in sin my mother conceived me.
 6 Behold, You desire truth in the inward parts,
         And in the hidden part You will make me to know wisdom.
        
 7 Purge me with hyssop, and I shall be clean;
         Wash me, and I shall be whiter than snow.
 8 Make me hear joy and gladness,
         That the bones You have broken may rejoice.
 9 Hide Your face from my sins,
         And blot out all my iniquities.
        
 10 Create in me a clean heart, O God,
         And renew a steadfast spirit within me.
 11 Do not cast me away from Your presence,
         And do not take Your Holy Spirit from me.
        
 12 Restore to me the joy of Your salvation,
         And uphold me by Your generous Spirit.
 13 Then I will teach transgressors Your ways,
         And sinners shall be converted to You.
        
 14 Deliver me from the guilt of bloodshed, O God,
         The God of my salvation,
         And my tongue shall sing aloud of Your righteousness.
 15 O Lord, open my lips,
         And my mouth shall show forth Your praise.
 16 For You do not desire sacrifice, or else I would give it;
         You do not delight in burnt offering.
 17 The sacrifices of God are a broken spirit,
         A broken and a contrite heart—
         These, O God, You will not despise.
        
 18 Do good in Your good pleasure to Zion;
         Build the walls of Jerusalem.
 19 Then You shall be pleased with the sacrifices of righteousness,
         With burnt offering and whole burnt offering;
         Then they shall offer bulls on Your altar.