This is a psalm of David that many believe is written from personal experience. He is joyful because he know that God has completely forgiven him. This joy and relief comes after he acknowledges his sin and confesses (agrees with God that he has sinned). God has forgiven him and he knows that God will forgive everyone who acknowledges and confesses their sin. If they’re in Christ, their sins are covered by His blood!
David then instructs his readers saying that God will teach and guide the person who is sensitive to Him. If we confess our sins and grow in sensitivity to His Word, He will direct us in His ways. We’re not to be stubborn or self‑willed, like a horse or mule, so that God has to put a bit and bridle on us to direct us. Rather, we are to be sensitive to His Spirit and His Word. God will direct the forgiven sinner into paths of righteousness.
Whether David wrote this psalm because of his sin with Bathsheba or from some other incident, it shows that he knew how it felt to have the joy and relief of experiencing God’s forgiveness. He instructs us so that we too can know the blessings of God’s forgiveness.
David ends the psalm by contrasting the wicked, who have many sorrows, with the righteous, who are surrounded by the Lord’s unfailing love. The righteous are not those who never sin, but rather those “upright in heart” because they have confessed their sins. The thought of God’s mercy to sinners who don’t deserve it causes David to break forth with joy . Those in Christ are free from the weight of their sins, free from condemnation, because Christ has paid the penalty! There is no greater joy than that of knowing that your sins are totally forgiven.