Anger

... the monk Evagrius, the first to write down and attempt to codify the beliefs and practices of the desert monks with regard to sin (which they called "demons" or "bad thoughts"), not only provides me with a means of understanding my own "bad thoughts" but also with the tools to confront them. His view of anger is typically sensible. Anger, he wrote, is given to us by God to help us confront true evil. We err when we use it casually, against other people, to gratify our own desires for power or control.

The Cloister Walk