Mind

"Heaven is all health; and the more deeply heavenly influences are realized, the more sure will be the recovery of the believing invalid. The true principles of Christianity open before all a source of inestimable happiness. Religion is a continual wellspring, from which the Christian can drink at will and never exhaust the fountain. 

The condition of the mind affects the health of the physical system. If the mind is free and happy, from a consciousness of rightdoing and a sense of satisfaction in causing happiness to others, it creates a cheerfulness that will react upon the whole system, causing a freer circulation of the blood and a toning up of the entire body. The blessing of God is a healing power, and those who are abundant in benefiting others will realize that wondrous blessing in both heart and life" (Counsels for the Church, page 216).