Why should we mourn for our sins according to the Bible?

In Psalm 119:136, the psalmist weeps for those who do not keep God's law, but he also deeply mourns his own failure to fully obey it. This mourning is a godly sorrow that acknowledges our inherent sinfulness and failure to meet God's perfect standards. Such an attitude drives us to seek God's mercy and grace in Christ, leading to repentance and a deeper relationship with Him. Mourning for sin allows believers to experience the weight of grace fully, knowing that in Christ, we have forgiveness and righteousness, which produces a humble and contrite heart that is favored by God.