David had been anointed to be the King of Israel. This was not lost on him. He fully expected that anointing to be effected through his words and actions on behalf of the Lord for the protection of His people.
It was the words of Samuel which propesied David^s office that empowered David to fill his calling. It was David^s faith in the words spoken over him.
Christ has anointed us to manifest as SonsOfGod. He has spoken over us. Believe His Words and manifest His power by His HolySpirit.