The majority of evils people commit are the result, not of an evil will, but of the dissemination of evil thoughts which people accept and follow uncritically.
Material results are the manifestations of unseen forces; an artillery shell that comes to us was shot from an unseen cannon at an unknown time. In the same way, all important events originate in a thought.
Our actions are neither as good nor as vicious as our desires.
—Luc De Vauvenargues
Think only good thoughts, and with time they will become good deeds.
Thoughts which create evil actions are much worse than the acts themselves. You can stop doing a bad thing, and repent, and not repeat it. But bad thoughts are repeated again and again, and cause other bad actions; bad thoughts follow one after another.
Think good thoughts, and your thoughts will be turned into good actions. Everything begins in thought. Guiding your thoughts is one of the keys self-perfection. If you suffer misfortunes in your life, look for their cause, not in your actions, but in the thoughts which inspired them, and try to improve those thoughts. If you are inspired by an event in your life, look for its origins in your previous thoughts which caused the event.