To be free of sin. If you truly believe in God, and you truly believe God can forgive your sins, then confession of sin will come with a genuine letting go of guilt. God is love. Judas, even though he repented of his betrayal of Jesus, lacked true confidence in God. So guilt is a kind of worship and faith in pain, violence, and sin.
Guilt is a version of lust of the flesh.
God is greater than all of my sins. The vastness of the Universe and Eternity are greater than all of my sins. The wicked man holds sins in his heart. The first sin leaves a seed of pain in the heart of a young boy. He feels guilt for his trespass.