Effort is required to do good deeds, but even more so to abstain from doing evil.
Nothing is more important than abstinence for the attainment of holiness. Abstinence must be one of the earliest habits. If it is, abstinence will fortify into virtue. Once fortified by virtue, there is nothing that one cannot overcome.
Everything that people admire so much, everything they care so much about and work so hard to obtain, all that does not bring them the tiniest bit of happiness. While they are busy, they think that the good lies in the object of their pursuit. But the moment they get the object of their desire, they begin to worry again, feeling distress and envy over something else which they do not yet possess. Tranquility is not reached by the satisfaction of your idle desires, but, on the contrary, by ridding yourself of such desires.
If you want to be convinced that this is true, apply even half of the effort which you have until now been spending on the attainment of your empty desires on freeing yourself from them, and you will quickly see that doing this will bring you much more peace and happiness.
— After Epictetus
Glory to the one who does not yield to temptation. God tests everyone: one is tempted by riches, another by poverty. The rich: will he open his hand to the needy? The poor: will he bear his suffering obediently and without complaint?
— The Talmud
I will call a true charioteer only the one who can control his rage, which rushes like a swift chariot; the others are powerless, they are merely holding the reins.
— The Dhammapada
If, burdened with unpleasant business, you feel an onset of rage or indignation, hasten to retreat into your own self and do not lose self-control. The more we practice using our willpower to restore the tranquility of our soul, the easier it becomes for us to maintain a tranquil spiritual state.
— Marcus Aurelius
No matter how many times you find yourself falling, failing to achieve victory over your impulses, do not despair. Any amount of effort spent in the struggle weakens the impulse and makes victory over it easier.