With Dr. Justin Bass The Philistines and Israelites were at war. Goliath, a giant Philistine warrior, challenged the Israelites to send a champion to fight him. David, a young shepherd boy, volunteered to fight Goliath. David defeated Goliath with a sling and a stone, and the Israelites were victorious. This passage teaches us that God can use anyone, no matter how young or insignificant they may seem, to accomplish His purposes.