Chapter 17 narrates Jesus' transfiguration and the healing of a boy the disciples could not set free. Jesus explains that their lack of success was due to the smallness of their faith. Faith the size of a mustard seed, however small it seems, is enough when placed in the right God. The lesson is not about the size of faith, but about its object. Our limitations do not define what God can do. He can accomplish the impossible when we sincerely trust him.