Over the summer, we looked at the lives of the first kings of Israel: Saul and David. There were many differences between them. Saul was large and looked like a massive warrior. David was smaller, younger, and taught himself to fight as a shepherd in the country. Ultimately, they were both warriors and both kings. And in one way or another, they both believed in the God of Israel. But though they both believed in God, it would be wrong to say that they both put their faith in him.
In fact, the most fundamental difference between the two was a difference of the heart. This is what God explicitly says to Saul in 1 Samuel 13:14:
But now your kingdom will not endure; the LORD has sought out a man after his own heart and appointed him leader of his people, because you have not kept the LORD’s command.
God made clear that David would be different in two ways. First, his heart would be for God rather than for himself, his own power, and his own survival. Second, David would obey the Lord, and if he ever failed, his repentance would be real.