Byzantine Church Father who concerned himself with the most important question in Christianity: the salvation and deification of mankind. He came up with the idea of hesychasm, a way to cleanse the mind by shutting off all physical sensations, images and concepts. This is supposed to allow you to receive and conserve energy from the Holy Spirit. He spent his life in quiet reflection and in combat with those who disagreed with him. He endorsed the Christian conversion of the Turks. Gregory’s advice on how to fight sinful sexual desires helped us write the chapter on Christian asceticism.