I Samuel 17:4
The Philistines had a champion, but God’s man David would be the conqueror of the Philistine’s champion. The King of kings had His hand upon His man. The very heart and soul of the wonderful account of David’s victory over the giant Goliath is the faith David had in God to win the victory (take time to read this wonderful account in David's life). Those in the camp of Israel didn’t believe in David and those in the camp of the Philistines certainly didn’t believe that the shepherd boy had a chance with a sling and five stones. I would rather be an instrument in the hands of the Living God than a pawn in the hands of the devil.
God has, God can, and God will use the most unlikely person to do a powerful and mighty work. Praise God!! Mark it down, there will be doubters, but don't you dare stop. There will be those, who though you may not hear their words they will scoff and question the validity of what you are called to do. Don’t you dare stop! The enemy will be sure to show himself. He will whisper doubt in your ear while knocking on your heart's door like an attacking lion. Don't you dare stop! You will know and you will feel the resistance and the strain of the enemy. Don’t you dare stop! Stand tall and strong in the power of God and in His might. Never allow the lack of faith of another to dilute your trust in God, and what God has called you to do.