Ellen G. White, Counsels on Health, p. 577

“Eating has much to do with religion. The spiritual experience is greatly affected by the way in which the stomach is treated. Eating and drinking in accordance with the laws of health promote virtuous actions. But if the stomach is abused by habits that have no foundation in nature, Satan takes advantage of the wrong that has been done and uses the stomach as an enemy of righteousness, creating a disturbance which affects the entire being. Sacred things are not appreciated. Spiritual zeal diminishes. Peace of mind is lost. There is dissension, strife, and discord. Impatient words are spoken and unkind deeds are done; dishonest practices are followed and anger is manifested—and all because the nerves of the brain are disturbed by the abuse heaped on the stomach.”

Ellen G. White, Education, p. 197

Electric Power of Brain Vitalizes System—”The influence of the mind on the body, as well as of the body on the mind, should be emphasized. The electric power of the brain, promoted by mental activity, vitalizes the whole system, and is thus an invaluable aid in resisting disease. This should be made plain. The power of the will and the importance of self-control, both in the preservation and in the recovery of health, the depressing and even ruinous effect of anger, discontent, selfishness, or impurity, and on the other hand the marvelous life-giving power to be found in cheerfulness, unselfishness, gratitude, should also be shown.

Ellen G. White, Messages to Young People, p. 134

“He that is slow to anger is better than the mighty; and he that ruleth his spirit than he that taketh a city.” He has conquered self—the strongest foe man has to meet.”

“The highest evidence of nobility in a Christian is self-control. He who can stand unmoved amid a storm of abuse is one of God’s heroes.

To rule the spirit is to keep self under discipline; to resist evil; to regulate every word and deed by God’s great standard of righteousness. He who has learned to rule his spirit will rise above the slights, the rebuffs, the annoyances, to which we are daily exposed, and these will cease to cast a gloom over his spirit.”

“It is God’s purpose that the kingly power of sanctified reason, controlled by divine grace, shall bear sway in the lives of human beings. He who rules his spirit is in possession of this power.”

Bible texts on anger and more – 4 (all verses are the King James Version):

Proverbs 22:24 – Make no friendship with an angry man; and with a furious man thou shalt not go:
Proverbs 25:23 – The north wind driveth away rain: so doth an angry countenance a backbiting tongue.
Proverbs 29:22 – An angry man stirreth up strife, and a furious man aboundeth in transgression.
James 3:6-12:6 And the tongue [is] a fire, a world of iniquity: so is the tongue among our members, that it defileth the whole body, and setteth on fire the course of nature; and it is set on fire of hell.7 For every kind of beasts, and of birds, and of serpents, and of things in the sea, is tamed, and hath been tamed of mankind:8 But the tongue can no man tame; [it is] an unruly evil, full of deadly poison.9 Therewith bless we God, even the Father; and therewith curse we men, which are made after the similitude of God.10 Out of the same mouth proceedeth blessing and cursing. My brethren, these things ought not so to be.11 Doth a fountain send forth at the same place sweet [water] and bitter?12 Can the fig tree, my brethren, bear olive berries? either a vine, figs? so [can] no fountain both yield salt water and fresh.