Everyone knows the story of David and Goliath, but even in his victorious moment, David had several points when he could have chosen differently or even could have given up.  We know the story, though, because he kept moving forward, kept believing, and didn't let those who didn't believe in him stop him.  It's hard to do anything when it feels like no one believes in you, but with faith, with preparation, with hope, not even that can stop you.