Matthew 17:20

17:20 He told them, “It was because of your little faith. I tell you the truth, if you have faith the size of a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move; nothing will be impossible for you.”

Matthew 21:32

21:32 For John came to you in the way of righteousness, and you did not believe him. But the tax collectors and prostitutes did believe. Although you saw this, you did not later change your minds and believe him.