Sin is so filthy that we rightly feel we need to cover our sins so nobody sees them. Our attempts at covering our sin are very inadequate though. Scripture exposes our true spiritual state no matter how well we try to cover our sin, and even are most covered sins are exposed to God’s all-seeing eyes.
For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and of spirit, of joints and of marrow, and discerning the thoughts and intentions of the heart. And no creature is hidden from his sight, but all are naked and exposed to the eyes of him to whom we must give account.Hebrews 4:12-13 (ESV)
When we cover our sin, God exposes it and makes us give account. But, when we decide instead to expose our sins to the LORD, then He covers them with forgiveness, and once God covers a sin, then nobody can uncover it.
Psalm 32:1 affirms that forgiveness covers our sin
Blessed is the one whose transgression is forgiven, whose sin is covered.Psalm 32:1 (ESV)
How was David’s sin covered by Divine forgiveness? He had decided to uncover his sin to God
I acknowledged my sin to you, and I did not cover my iniquity;Psalm 32:5 (ESV)
Sin is ugly, but human attempts at covering it make it even worse. But when we confess our sins to the Lord, He forgives, and not only covers our sin, but also cleanses us from it (1 John 1:9).