The people of Israel weren't getting along with their neighbors, the Philistines.  Each country sent their army to the border, and the armies camped very close together. 

The Philistines had a lot of giants in their army. One of the strongest and biggest giants was named Goliath.  He was over nine feet tall.  Goliath was covered with armor to protect him and carried a big spear.  Every morning and evening, Goliath challenged the Israelites. "I dare you to find one man to fight me.  If he can beat me we will become your servants, but if I win you will all become our servants." For over a month, no one accepted Goliath's challenge.

David was a shepherd.  His three oldest brothers were in the Israeli army.  Their father Jesse told David to take some food to his brothers and report back about how they were doing.  When David got to the camp he heard Goliath daring anyone to fight him.  David asked why no one would fight Goliath, and the soldiers said that Goliath was so big they were all scared of him.  

David was not afraid.  When King Saul heard about the young boy who wanted to fight Goliath, he talked to David and told him he was too young, too small, and had no military experience.  David told the king that God would keep him safe fighting Goliath just as God had protected him when he fought lions and bears as a shepherd.

King Saul was impressed by David's courage and decided to let him fight Goliath.  David refused to wear armor or carry a soldier's weapons.  He went to a nearby stream and found five smooth stones.  Armed only with the stones and his slingshot, David walked up to Goliath and said he was taking the giant's challenge.  Goliath laughed and laughed at the little boy the Israelites had sent to fight him.

Goliath thought that when he came closer to David that the young boy would run away.  Instead, David reached into his pouch and pulled out a stone, put it into his slingshot and shot it at Goliath.  The stone hit him right between his eyes and Goliath fell on his face with a loud thud.