James 1:6-8 (NIV)
6But when he asks, he must believe and not doubt, because he who doubts is like a wave of the sea, blown and tossed by the wind.
7That man should not think he will receive anything from the Lord;
8he is a double-minded man, unstable in all he does.
Matthew 14:30-32 (NIV)
30Then Peter got down out of the boat, walked on the water and came toward Jesus. But when he saw the wind, he was afraid and, beginning to sink, cried out, “Lord, save me!”
31Immediately Jesus reached out his hand and caught him. “You of little faith,” he said, “why did you doubt?”
32And when they climbed into the boat, the wind died down.