We are God’s workmanship, and His Word declares that we are “fearfully and wonderfully made.” He has prepared this living habitation for the mind; it is “curiously wrought,” a temple which the Lord Himself has fitted up for the indwelling of His Holy Spirit. The mind controls the whole man. All our actions, good or bad, have their source in the mind. It is the mind that worships God and allies us to heavenly beings. Yet many spend all their lives without becoming intelligent in regard to the casket [the human body] that contains this treasure.—Child Guidance, 360.
All the physical organs are the servants of the mind, and the nerves are the messengers that transmit its orders to every part of the body, guiding the motions of the living machinery. Exercise is an important aid to physical development. It quickens the circulation of the blood, and gives tone to the system. If the muscles are allowed to remain unused, it will soon be apparent that the blood does not sufficiently nourish them. Instead of increasing in size and strength, they will lose their firmness and elasticity, and become soft and weak. Inactivity is not the law the Lord has established in the human body. The harmonious action of all the parts—brain, bone, and muscle—is necessary to the full and healthful development of the entire human organism....
The appetites and passions must be controlled, that through them we shall not weaken or defile God’s human temple.
Anything that lessens the physical power enfeebles the mind, and makes it less clear to discriminate between good and evil, between right and wrong. This principle is illustrated in the case of Nadab and Abihu. God gave them a most sacred work to perform, permitting them to come near to Himself in their appointed service; but they had a habit of drinking wine, and they entered upon the holy service in the sanctuary with confused minds.
There was the sacred fire, which was kindled by God Himself; but they used the common fire upon their censers, when they offered incense to ascend as a sweet fragrance with the prayers of God’s people. Because their minds were clouded by an unholy indulgence, they disregarded the divine requirement; “and there went out fire from the Lord, and devoured them.”...
It is the duty of each student, of each individual, to do all in his power to present his body to Christ, a cleansed temple, physically perfect as well as morally free from defilement—a fit abode for God’s indwelling presence.—Fundamentals of Christian Education, 426-428. RC 149
Never allow yourself to talk in a hopeless, discouraged way. If you do you will lose much. By looking at appearances and complaining when difficulties and pressure come, you give evidence of a sickly, enfeebled faith. Pr 311
"For God hath not given us the spirit of fear; but of power, and of love, and of a sound mind." 2 Timothy 1:7 (King James Version)