The prayer of a righteous man availeth much.
When the disciples failed to heal a young boy, Jesus chastised them for their weakness: “Oh faithless and perverse generation, how long shall I be with you? How long shall I bear with you?” After healing the boy himself he told them, “I say to you, if you have faith as a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move; and nothing will be impossible for you.” And then he added, “But this kind does not go out except by prayer and fasting.”
How are we to pray if we wish to move mountains or drive out demons? We begin by asking for God’s mercy on our souls. Listen to what St. Augustine had to . . .