According to Paramahansa Yogananda:
Jesus said Man shall not live by bread alone but by every word that proceedeth out of the mouth of God.
The "word" is life energy or cosmic vibratory force. The "mouth of God" is the medulla oblongata in the posterior part of the brain, tapering off into the spinal crd. This, the most vital part of of the human body, and it is the divine entrance ("mouth of God") for the "word" or life energy by which man is sustained. In the Hindu and Christian scriptures Aum or Amen is known as the "word".
It is that Perfect Power alone that heals; all external methods of stimulation only cooperate with the life energy and are valueless without it.
LyricalOne 