Quotes from the Saints
The Four Hundred Chapters on Love:
159. Keep yourself away from self love, the mother of vices, which is the irrational love of the body. For from it surely arise the first three passionate and capital thoughts, gluttony, greed, and vainglory, which have their starting point in the seemingly necessary demands of the body and from which the whole catalogue of vices comes about. Therefore, as was said, one must necessarily keep away from and do battle with this self love with full determination, for when this is overcome then are all its offspring likewise brought into line.
161. It is said that the supreme state of prayer is when the mind passes outside the flesh and the world and while praying is completely without matter and form. The one who preserves this state without compromise really "prays without ceasing."
167. It is said that there are five reasons why we are allowed to be warred upon by the demons. First, so that in offensive and defensive battle, we come to distinguish virtue and vice. Second, that in acquiring virtue by struggles and toil we shall hold on to it firmly and steadfastly. Third, that while advancing in virtue we do not become haughty but learn rather to be humble. Fourth, that having experienced vice we will hate it with a consummate hate. Fifth, and most important, that when we become detached we do not forget either our own weakness or the power of the one who has helped us.
St. Maximus the Confessor