David was "a man after God's own heart". This was not a condition exclusive to him, but his path represents the model of the "overcomers" who likewise come to know and express God to that depth.

Off the top of my head, I recall the scene where David cut a fringe off of Saul's robes as he was taking a leak - Dave later showed Saul this as proof that he had the opportunity to kill him, but refrained from doing so because it wasn't right. The moral is to forfeit the notion of retaliation to the Father instead of taking such matters into our own fleshly hands.