David served God in many capacities--from simple shepherd boy to heroic ruler. Looking at the various stages of his life, we can see clearly how his godly devotion allowed the Lord to use him mightily.
Shepherd: David was anointed king long before commanding anything other than sheep (1 Sam. 16:1-13). Protecting the sheep was a job he took seriously, even killing a lion and a bear to do so. During those days, he learned to be strong and brave, and to take care of creatures weaker than himself. An early life of obedience to his human father taught him the humility he would later need in order to depend on God.
Psalmist: David's writings reveal his hunger for God. He is open about issues like fear, depression, defeat, loneliness, and sorrow. By describing valley experiences and communing with the Father in the night watches, David provided us with intimate glimpses of the God he knew so well.
Commander: Starting with David's encounter with Bathsheba, the king's life was plagued by heartache, pain, suffering, and conflict. David had sinned greatly, but God forgave him and continued to use him. He ruled Israel for 40 years, and his people called Jerusalem the "City of David." His restoration teaches us about the consequences of sin and the limitlessness of God's grace.
King David served God's purpose when he lived, and continues to do so hundreds of years later--every follower of Christ has been blessed by David's obedience, service, and literary skill. He is a great example of what God can accomplish through us if we yield our life to Him.
~Dr. Charles Stanley~