A stark contrast certainly existed between King David and King Saul as it came to God's presence in their leadership.  The difference between the two men was that David sought to bring glory to the Lord and Saul sought to bring glory to himself.  Since David's efforts were directed at the Lord, his work prospered under God's hand.  No verse better summarized this than 2 Samuel 5:10, "And David became greater and greater, for the Lord, the Gos of hosts, was with him."  God's presence guided David's leadership, and though his life was not marked by perfection (after all, whose life is marked by perfection), God guided and brought Israel into a new era of recognizing the Lord and submitting themselves to Him.  Godly leaders will always bring their followers into a recognition of and a submission to the Lord.  And when they do that, God's hand will be upon all that they do.