As the Philistine moved closer to attack him, David ran quickly toward the battle line to meet him. Reaching into his bag and taking out a stone, he slung it and struck the Philistine on the forehead. The stone sank into his forehead, and he fell facedown on the ground.
1 Samuel 17:48-49
When you feel powerless, like your life has no meaning, that you could never accomplish anything of great merit, remember the story of David. An average person who stood up to a giant when nobody else had the courage. David did not rely on his own understanding, he relied on God. Armed with only a sling and some stones, he knew that with God there was noting he couldn’t do. We have that same power at our disposal today. God can do great things through you, all you have to do is step out in faith.