Lack of Faith Rebuked Mat 17:9-21
As Raphael suggests in his great painting, there is a close connection between the mountain and the valley. The glory of the one did not make our Lord indifferent to the bitter need of the other. It seems as though He desired to impress on us the great truth, that we must have the seclusion and exaltation of communion with God before we can successfully deal with the anguish and terror that devastate human lives. See Mat 17:21 .
In Mat 17:17 our Lord grieves over the unbelief of His disciples. Though they had enjoyed His careful teaching, they had failed to grasp His secret, which He here again elaborates. Faith is openness to God. It is the lifting of the curtain, that the healing light may enter. The tiny seed unlocks its little doorway to welcome the entering life of nature; and as this continues to enter, it forces the rootlet downward and the green shoot upward. It is thus also with the life of God in the soul. Let this life of God in and there is no limit to what it will effect.