How a Mustard Seed of Faith Moves a Mountain of Grace

Jesus descended from the Mount of Transfiguration to find His disciples in a pickle. A man had brought his terribly afflicted son to the disciples for a healing blessing, but they had been unable to provide the cure. The father approached Jesus and begged for help, and Jesus immediately cured the boy. The disciples then came to Jesus and asked what had gone wrong that they had been unable to heal the boy.  Jesus spoke bluntly. "Because of your unbelief." He then taught them the parable of the grain of mustard seed, saying that even the tiniest bit of faith would be sufficient to move a mount. But then He added this footnote to his teaching: 

Howbeit this kind goeth not out but by prayer and fasting.
--Matthew 17:21

Prayer and fasting are needful preparations for the development and exercise of faith unto power. Prayer puts us in direct connection with God, the source of all power. In sincere prayer we subject ourselves to His will and we learn His intentions for us. His Holy Spirit makes known to us the mountain He wants to move with us. 

By going to Him often and listening carefully, we can learn what He expects us to do and when it is time for us to step back and watch Him work. 

Our shovelfuls may seem insignificant, but they are our necessary contributions, not in moving the whole mountain, but in building our strength and convincing us that only God's power can complete the job. He asks us to try on our own, not to discourage us, but to help us see the reality of the task and convince ourselves of our insufficiency. Then, when He steps in with His power and moves the whole mountain with a single sweep of His hand, we can better appreciate the gift of His grace.