The faith which creates powerful praying is the faith which centers itself on a powerful Person. Faith in Christ's ability to do and to do greatly, is the faith which prays greatly. Thus the leper lay hold upon the power of Christ. "Lord, if Thou wilt," he cried, "Thou canst make me clean." In this instance, we are shown how faith centered in Christ's ability to do, and how it secured the healing power.
Taken from the book The Essentials of Prayer by E.M. Bounds 1835-1913