Leonard Ravenhill on faith:
Now obviously no faith is required to do the possible; actually only a morsel of this atom-powered stuff is needed to do the impossible, for a piece as large as a mustard seed will do more than we have ever dreamed of. Again and again God asks men to do not what they can, but what they can’t.
Matthew 17:20 And Jesus said unto them, Because of your unbelief: for verily I say unto you, If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you.