I'm just trying to figure out how David became a man willing to stand up to a giant. Some estimates put him at about age 22-25 when he stood up to Goliath, so that means he spent 12+ years looking after sheep for his father, a task left to the youngest of the family while the elder brothers took on the more manly jobs. Somewhere in that time, David learned to trust the Lord in a way many of us never do. He learned to rely on the Lord for help.
It seems to me the life of a shepherd is a secluded one. I can’t imagine being gone from home for days without some kind of other people around. There, in the pasture land, with no tvs, ipods or game systems to distract, David formed a relationship with the Almighty. There, he honed the techniques of his trade using rod, staff, sling and stone. He learned what worked and what didn’t. He learned that God would protect him. David speaks of his experiences to King Saul:
But David said to Saul, "Your servant used to keep sheep for his father. And when there came a lion, or a bear, and took a lamb from the flock, I went after him and struck him and delivered it out of his mouth. And if he arose against me, I caught him by his beard and struck him and killed him.
Your servant has struck down both lions and bears, and this uncircumcised Philistine shall be like one of them, for he has defied the armies of the living God." And David said, "The LORD who delivered me from the paw of the lion and from the paw of the bear will deliver me from the hand of this Philistine."… 1Sm. 17:34-37 (all ESV)
David had much experience with predators after the sheep. He did whatever was necessary to save the sheep. When a predator took a sheep, David beat or wounded it and saved the sheep. If the animal went after David, he restrained it by its hair and killed it. Ummm… that’s a little too bold for me! Why was he so courageous? Read v. 45-47 and his bold proclamation to Goliath of God’s deliverance, "this day the LORD will deliver you into my hand" (v.46).
See, David wasn’t relying on his own strength. He was trusting God to win the battle, for it was His battle. "…the LORD saves not with sword and spear. For the battle is the LORD's, and he will give you into our hand." (v.47). In effect, David wasn’t ‘seeing’ the 9 to 12 foot giant before him wearing the 150ish pound coat of mail, and carrying a spear with a 16ish pound spearhead. He was ‘seeing’ Almighty God who would save His people from the ‘jaws’ of the enemy.
And that is why David was so bold as to run "…quickly toward the battle line to meet the Philistine." (v.48)
Oh Lord, help me trust you that way!