Yoda moves X-Wing with the Force

Luke during training is learning to use the force. Yoda has him attempt to retrieve his X-Wing fighter from the swamp - Luke fails. "You want the impossible" he tells Yoda. Yoda proceeds to remove it from the swamp. "I don't believe it" Luke exclaims. "That is why you fail." Yoda replies.
Lack of belief is also why people fail to please God Heb 11.6 and stumble in their Christian walk.