He who has mastery over his incensive power has mastery also over the demons. But anyone who is a slave to it is a stranger to the ways of the Saviour, for as the Saviour enjoined us: 'Learn from Me; for I am gentle and humble in heart: and you will find rest for your souls' (Mt. 11:29). Now if a man abstains from food and drink, but becomes incensed to wrath because of evil thoughts, he is like a ship sailing the open sea with a demon for a pilot.
Evagrius PonticusDo not be troubled if you do not immediately receive from God what you ask Him; for He desires to do something even greater for you, while you cling to Him in prayer.
Evagrius PonticusIf your spirit still looks around at the time of prayer, then it does not yet pray as a monk. You are no better than a man of affairs engaged in a kind of landscape gardening.
Evagrius Ponticus