Abba Pityrion, the disciple of Abba Anthony said, “If anyone wants to drive out the demons, he must first subdue the passions; for he will banish the demon of the passion which he has mastered. For example, the devil accompanies anger; so if you control your anger, the devil of anger will be banished. And so it is with each of the passions.”
We are all called to engage spiritual warfare in our lives. We all have temptations, weaknesses in our lives, passions which we fall for again and again. Though early monks and nuns went out to the desert to fight against demons, they found the main conflict was one which was within. They came to understand that the way to overcome the influence of demons was to come to know oneself, and by coming to know oneself, one can see the spiritual traps one faced and not fall for them when encountered. While there can be more significant ways for demons to hurt us (oppression, obsession and possession), most demonic conflict is psychological. C.S. Lewis’ Screwtape Letters presents the reality these monks and nuns came to know, as they saw the subtle influence demons can have on us and our way of thinking. They do not force us to act, but, if we don’t confront them, they engage us, and influence us, just like any and every social interaction ends up influencing our perception of the world.
Talking about the primary means of demonic influence in our lives as being psychological is not to say they cannot oppress is – they can, if we let them; we have to diligently confront them whenever they circle around us trying to cause us distress. They play mind games with us, distracting us from where we can best overcome them. They thrive upon us when they lead us to sin. They surround us when we falter. They mock us and make us feel as if there is nothing we can do. Then they can interact with us, cause us real physical harm. A weakened spirit leads to a weakened body. But, we must not give up. The more we examine our lives, the more we know ourselves, the more we will know how and why temptations make us falter. We will know how to gain mastery over ourselves. Demons keep us fragmented, because they are the powers of chaos, sapping away at the good within. Evil corrupts and destroys, trying to take apart that which should be whole. Demonic presences in our lives, if left unchecked, can end up harming our lives, making us live in despair. The solution is spiritual warfare, founded upon self-knowledge. The more we know ourselves, the more we know who we are as a whole, the less demons can fragment us within and without.
 The Sayings of the Desert Fathers. Trans. Benedicta Ward (Kalamazoo, MI: Cistercian Publications, 1984), 200.