And when he had removed him, he raised up unto them David to be their king; to whom also he gave testimony, and said, I have found David the [son] of Jesse, a man after mine own heart, which shall fulfil all my will.
Note 8 at Ac 13:22: David was the second king of Israel and was called a man after God's own heart (here and 1Sa 13:14). His trust in God and refusal to accomplish God's will in an improper way concerning his predecessor, King Saul, is one of the greatest examples of faith in Scripture.
Seventy-three of the Psalms have been attributed to David, and his skillfulness in and love for music are well attested to in Scripture (1Sa 16:17-18; 2Sa 6:5, 23:1; 1Ch 16:7, 37-42, and 25:1).
Under God's guidance, David became a mighty military success. He expanded Israel's borders to the greatest extent of any of Israel's kings, putting garrisons in Damascus of Syria (2Sa 8:5-6).
David was a prophet as well as a king. He prophesied many events in the life of Jesus (partial list given in note 1 at Mt 26:24) and was repeatedly quoted by Jesus and the apostles. Ps 22 and 69 give some of the most detailed prophecies of Jesus' crucifixion of any Old Testament scriptures.