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 17:49 NIV)
David did not have faith in the small stone he got from his pouch.
He had faith that God could use a small thing to conquer the giant before him.
He believed that God could use a small stone placed in the hand of a young boy to change the momentum of a critical battle.
He believed in God.
He fought with faith.
What small thing has God already placed in your hand?
Place your faith in God then fight.
He will use the small thing he has placed in your hand to do the big thing you have been praying for.