“The thoughts that vex and annoy us have many distinctions: a provocation, or an attack of a thought, is not a sin but is a test of our free will, to what it is inclined—to the thought or to opposition of it. However, when there is agreement and communion with these passions it is considered to be a sin and repentance is needed. He who does not have the strength to oppose them himself must hasten to God, cast down his infirmity and implore His help and the help of the mother of God. When someone is conquered by thoughts it is a sign that pride preceded them, and therefore, he must humble himself more.”
+ St. Macarius of Optina, quoted from Living Without Hypocrisy: Spiritual Counsels of the Holy Elders of Optina