What does the Bible say about mourning over sin?

The Bible teaches that mourning over sin is a reflection of a heart that recognizes the gravity of sin and its separation from God. In Matthew 5:4, it states, 'Blessed are they that mourn: for they shall be comforted.' This mourning is not akin to grief over loss but a deep sorrow for the sinful state of one's heart. It reflects a spiritual poverty that leads to God's grace, where believers, like David, express in Psalm 38 their continuous struggle against sin and earnest longing for God's mercy. The proper context for understanding this mourning is through the lens of the cross, as true mourning is rooted in recognizing how serious sin is, ultimately leading believers to comfort through Christ's redemptive work.