Matthew's Gospel records that the disciples once failed to heal an epileptic boy whom their Master afterwards healed quickly and easily. His answer to their inquiry as to the reason for that failure placed the responsibility squarely upon unbelief, or lack of faith. His words (Matt. 17:20), "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," firmly establish the scientific fact that faith is of vital importance to every demonstration of healing.
The Master, in comparing a mustard seed with a mountain, presented a contrast of tremendous significance to the human mind. It is clear, however, that his measure was not according to material proportions, but was in accordance with the might of spiritual power over material resistance. In this comparison he was pointing out to his disciples that the massive bulk of a mountain of materiality does not necessarily represent power and immovability; but that a true sense of faith is based upon spiritual reality, and is thereby endowed with a power which outweighs the mountain of mortal seeming and removes it.
Mary Baker Eddy, through her study of the words and works of the Master, so clearly discerned the importance of faith in connection with healing that she gave to her followers in her writings on Christian Science a wealth of counsel on faith, showing what it is, what it does, and how it is to be attained. At the very beginning of the first chapter of her textbook, "Science and Health with Key to the Scriptures," she says (p. 1), "The prayer that reforms the sinner and heals the sick is an absolute faith that all things are possible to God,—a spiritual understanding of Him, an unselfed love."
