The Spirit of the LORD came mightily upon David from that day forward 1 Samuel 16:13
Saul was rejected as a king because He obeyed partially (Lord asked to destroy whole Amalekities but He spared the best). Do we deny all sins or are we still enjoying some secret sins, or still mind is full of lust.
Lord chose David in His place. The reason what Lord says is, I look at persons heart. Even if you are not of great talent, Lord will use you if you a clean and committed heart.
When Lord’s call was put upon David (through Samuel), immediately Spirit of the Lord came upon Him mightily and from that day, He was anointed. Are you Spirit filled? Are you chosen by God? Surrender now and receive the anointing.
Lord, please forgive my sins. Lord, send me your Holy Spirit mightily into my life. Transform me that I will walk and live a life controlled by Holy Spirit. Amen.