Your success depends on ruling your spirit. Great men rule their spirits. They resist temptations to react or overreact. They restrain their emotions and manage them for good.
How safe are you from trouble? If you do not rule your spirit, you are vulnerable to say or do things that could cost you dearly. You may already be damaged by such actions.
Your spirit is your inner self, which controls your actions. When you do not rule your spirit, you are exposed and vulnerable to all sorts of folly and trouble. Like a defenseless city without walls in former times of marauding armies, so is the man who does not rule his own spirit and diligently keep it in the way of virtue, truth, and wisdom.
Your spirit includes your affections, appetites, and passions. A wise and noble man rules his spirit by his conscience and mind. He locks it down with chains of self-denial to keep ambition, anger, lust, pride, or revenge from breaking forth. He guides it by a mental commitment to hold fast honor, humility, righteousness, and virtue. He rules his thoughts, his desires, his inclinations, his resentments, and keeps them all in disciplined order.
A fool lets his spirit control his actions. He does not resist impulses from his spirit; he lets his spirit direct him; he forfeits the fight for character and godliness. He cannot do what he should; he cannot stop doing what he should not. Such men are often angry, generally foolish, often depressed, or always procrastinating, among other faults and sins. They never grow up, for they are controlled by childish passions of a depraved heart.
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