Psalm 51 is about sin as corruption, not just guilt, and for

Psalm 51 refuses to treat forgiveness as a legal pardon that lets life go back to normal; David’s plea is for God to do Genesis-level creation inside him because the real crisis is that the sinner himself is the broken instrument of worship and rule. That’s why sacrifice is useless until the self is shattered into honesty—and why private bloodguilt is portrayed as a public threat to Zion’s stability.