Just as a dirty bowl would need to be cleansed before it can be of good use or whatever it holds will be contaminated. Reciting the sutras three hours or more daily for three years will deepen one's concentration. When one's concentration reaches a certain level, true wisdom can be revealed. It is the pure mind derived from practice of the Three Learnings of precepts, concentration and wisdom that are obtained from years of cultivation. A pure mind is one without discriminations or attachments.
Anger is like a fire, being one of the three poisons of the mind.
Once a person's anger flares up, all the merit and virtues accumulated from years of diligent cultivation completely disintegrate, sending the practitioner back to square one. One accumulates merit and virtue when one is able to end greed in addition to diligently cultivating giving and following the precepts. The practice of endurance, diligence and concentration enables one to preserve one's merit and virtue. A person who likes to practice giving and abides by laws and customs will accumulate good fortune. Understanding what one practices is essential to one's success.