St. Theodoros The Great Ascetic - 7 - 8

7. So long as the soul is in a state contrary to nature, running wild with the weeds and thorns of sensual pleasures, it is a dwelling-place of grotesque beasts. Isaiah's words apply to it: ass-centaurs shall rest there, and hedgehogs make their lair in it, and there demons will consort with ass«centaurs (cf Isa. 34:11, 14. LXX) - for all these animals signify the various shameful passions. But the soul, so long as it is joined to the flesh, can recall itself to its natural state at any time it wishes: and whenever it does so and disciplines itself with diligent effort, living in accordance with God's law, the wild beasts that were lurking inside it will take to flight, while the angels who guard our life will come to its aid, making the soul's return a day of rejoicing (cf. Luke 15:7). And the grace of the Holy Spirit will be present in it, teaching it spiritual knowledge, so that it may be strengthened in what is good and rise to higher levels.

8. The Fathers define prayer as a spiritual weapon. Unless we are armed with it we cannot engage in warfare, but are carried off as prisoners to the enemy's country. Nor can we acquire pure prayer unless we cleave to God with an upright heart. For it is God who gives prayer to him who prays and who teaches man spiritual knowledge.