Since the devil has as nourishment the passions and pleasures of the senses, he too will die as he is deprived of this nourishment. “The strong lion perishes for lack of prey” (Job 4:11). St. Neilos has noted that the devil is often referred to as an “ant-lion,” just as the passions are. This means that at first these passions appear as something very small, but later become great and strong like lions. Do you see, dear brother, what great enemies you have to defeat? Do you see that by cutting off the passions of the senses, you are also going to put Satan to death? But alas this cutting off and this victory cannot be won without a war. It is like the external wars, no one can win a victory without first waging a war against the enemy. It is certain that you have to experience a great struggle in each of your senses both from the point of view of habit and of the enemy.
For the bad habit desires to draw each sense toward its pleasurable object when it is present. On the other hand, the enemy desires to wage a great battle in the memory and imagination of the mind in order to achieve its consent to enjoy that pleasure, so that, in doing so, the devil can also enjoy the same pleasure. But you must stand courageously and never consent to the will of the enemy. Say to yourself that iambic proverb of St. Gregory the Theologian: “No one can excel by beginning from cowardice; it is the victories that bring praise.”
An ancient people recognized their children to be their genuine offspring only after placing before them a viper and observing them catch it courageously. You too, dear brother, must make the enemy realize that you are a true child of Christ Who is your heavenly Father, and who has overcome the passions and the devil-through the courage you demonstrate in fighting against the evil passions of your senses. And if the enemy stands to fight you, be not afraid to tell him what that brave Spartan said to Xerxes: “Oh king, you managed to sail the sea and to cut a channel across the peninsula of Athos, but you will not pass the side of one armed Spartan.” For this reason then show the enemy that you are not a slave of your senses, but lord and king. Show that you are not only flesh and blood, but a rational mind, appointed by God to be leader and sole ruler over the irrational passions of the body. Say to yourself that wise proverb about evil habits: “The best learning for man is to unlearn evil.” Now, if I have learned, wrongly, to give to my senses their sensual objects, and this wrong learning has brought about a bad habit, and this bad habit a still further bad condition, why can I not now learn to do the opposite? Let, therefore, the good learning become a good habit and the good habit a good and permanent condition. If, in doing this, I am to experience difficulties and bitterness at first, let me experience them. Afterward I will be able to experience both ease and joy. The first efforts to learn and practice the virtues and establish the habit of virtuous living are often very bitter and most difficult for the senses. The activity that follows after these initial efforts to acquire the habit of virtuous living is very easy, ineffably sweet, and enjoyable. Briefly we can say that angels are invisibly present, holding crowns in their hands. Christ himself is the one Who will crown you every time you are victorious in the battle against the evil passions of the senses and you do not succumb to them. St. Basil said: “Suffering brings glory, and tribulation brings crowns.” But you have been beaten once or twice (I hope not!). Be not completely overcome. Stand firm and courageous, calling upon God for help. If you do so, the grace of God will come directly to your help and will not leave you to be completely overcome by the enemy. Do you want to be sure of this? Follow me and let us travel to Sodom. Have you come? Behold the five kings of Sodom mentioned in Holy Scripture (Gen 14), who were then under the hegemony of the Assyrian king Chedorlaomer and who were paying tribute to him and to the other kings with him for ten years. In the thirteenth year they rebelled and did not want to pay the tribute to the Assyrian king, who then declared war on them. It appeared soon afterward that the five kings were subdued and captured by the Assyrians. What happened next? When Abram heard about this, he ran to their aid; he fought, he won, and he liberated them for the sake of his nephew Lot.
St. Nicodemos of the Holy Mountain - A Handbook of Spiritual Council – Chapter 8; Guarding All the Senses in General pp. 136-145 (“The Classics of Western Spirituality” series.)