'Have Faith' in the Bible

He said to them, "Because you have so little faith. For I tell you, if you have faith the size of a grain of mustard, you can say to this mountain, 'Move from here over to there!' and it will move, and nothing will be impossible for you."

Jesus answered, "I tell you, if you have faith and have no doubt, you will not only do what I have done to the fig tree, but even if you say to this mountain, 'Get up and throw yourself into the sea,' it will be done.