He believed

“Then all this assembly shall know that the LORD does not save with sword and spear; for the battle is the LORD’s, and He will give you into our hands.” 1 Samuel 17:47

How could David be so sure? Did he not see and hear the same enemy as his brothers and all the army of Israel? A blood-thirsty Philistine giant, polluting the very air with his pagan cursings!

And yet, David believed the LORD, and His promise to fight for Israel. He believed.