James 1:5-6 If any of you is lacking in wisdom, ask God, who gives to all generously and ungrudging, and it will be given you. But ask in faith, never doubting, for the one who doubts is like a wave of the sea, driven and tossed by the wind.Once upon a time a teacher along with his disciples lived in a hermitage. One day, one of the disciples had to go to the marketplace by crossing a small stream. There were stepping stones in this stream and one has to walk carefully in order to cross safely. As he started his journey, not too far into it, rain came pouring down heavily. He returned to his teacher and reported the problem. The teacher said, "You should have faith in God, as He will save you from all your problems."
The disciple obeyed his master and and resumed his journey. He kept reciting the name of God and while stepping on each stone, cleared all his hurdles and reached his destination safely.
After couple of days, the teacher himself had to go on the same route. When he reached the stream, he doubted whether or not God would save him. In his doubt, the teacher got drowned.
Moral: Faith saves us and doubt drowns us.