St. Theodoros The Great Ascetic - 16 -17

16. With those who live in the world and are associated with the material things that feed the passions, the demons wage war through practical activities; while with those who dwell in the wilderness, where material things are rare, they fight by troubling them with evil thoughts. This second mode of warfare is far more difficult to cope with; for warfare through things requires a specific time and place, and a fit occasion, whereas warfare of the intellect is mercurial and hard to control. But as our trusty weapon in this incorporeal fight we have been given pure prayer: that is why we are told to pray without ceasing (cf I Thess. 5:17), Prayer strengthens the intellect in the struggle, since it can be practiced even without the body taking part.

17. With reference to the perfect mortification of the passions St Paul says: 'They that are Christ's have crucified the flesh together with the passions and desires' (Gal. 5:24). For when we mortify the passions, utterly destroy desires, and subjugate the will of the flesh to the Spirit, we take up the cross and follow Christ (cf Matt. 16:24). For withdrawal from the world is nothing else but the mortification of the passions and the manifestation of the life that is hidden in Christ (cf Col. 3:3-4).