He that is slow to anger is better than the mighty; and he that ruleth his spirit than he that taketh a city. Proverbs 16:32. AG 256.1
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. AG 256.2
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.13Messages to Young People, 134. AG 256.3
The body is a most important medium through which the mind and the soul are developed for the upbuilding of character. Hence it is that the adversary of souls directs his temptations to the enfeebling and degrading of the physical powers.... The body is to be brought into subjection to the higher powers of the being. The passions are to be controlled by the will, which is itself to be under the control of God.... Intellectual power, physical stamina, and the length of life depend upon immutable laws. Through obedience to these laws, man may stand conqueror of himself, conqueror of his own inclinations, conqueror of principalities and powers of “the rulers of the darkness of this world,” and of “spiritual wickedness in high places” (Ephesians 6:12).... AG 256.4
The spirit that possessed Daniel, the youth of today may have; they may draw from the same source of strength, possess the same power of self-control, and reveal the same grace in their lives, even under circumstances as unfavorable. Though surrounded by temptations to self-indulgence, especially in our large cities, where every form of sensual gratification is made easy and inviting, yet by divine grace their purpose to honor God may remain firm. Through strong resolution and vigilant watchfulness they may withstand every temptation that assails the soul.14Prophets and Kings, 488-490. AG 256.5