Even a pious person is not immune to spiritual sickness if he does not have a wise guide -- either a living person or a spiritual writer. This sickness is called prelest, or spiritual delusion, imagining oneself to be near to God and to the realm of the divine and supernatural. Even zealous ascetics in monasteries are sometimes subject to this delusion, but of course, laymen who are zealous in external struggles (podvigi) undergo it much more frequently. Surpassing their acquaintances in struggles of prayer and fasting, they imagine that they are seers of divine visions, or at least of dreams inspired by grace. In every event of their lives, they see special intentional directions from God or their guardian angel. And then they start imagining that they are God's elect, and often try to foretell the future. The Holy Fathers armed themselves against nothing so fiercely as against this sickness -- prelest.
Just as our Lord is solicitous about our salvation, so too the murderer of men, the devil, strives to lead a man into despair... Judas the betrayer was fainthearted and unskilled in battle, and so the enemy, seeing his despair, attacked him and forced him to hang himself; but Peter, a firm rock, when he fell into great sin, like one skilled in battle did not despair nor lose heart, but shed bitter tears from a burning heart, and the enemy, seeing these tears, his eyes scorched as by fire, fled far from him wailing in pain.
A great effort and much toil are needed in prayer before we can reach a state in which our mind is no longer troubled, and so attain the inward heaven of the heart where Christ dwells. As St. Paul says, 'Do you not realize that Christ dwells within you, unless you are worthless?' (cf. 2 Cor. 13:5).
The body is a slave, the soul a sovereign, and therefore it is due to Divine mercy when the body is worn out by illness: for thereby the passions are weakened, and a man comes to himself; indeed, bodily illness itself is sometimes caused by the passions.
It is more serious to lose hope than to sin. The traitor Judas was a defeatist, inexperienced in spiritual warfare; as a result he was reduced to despair by the enemy's onslaught, and he went and hanged himself. Peter, on the other hand, was a firm rock: although brought down by a terrible fall, yet because of his experience in spiritual warfare he was not broken by despair, but leaping up he shed bitter tears from a contrite and humiliated heart. And as soon as our enemy saw them, he recoiled as if his eyes had been burnt by searing flames, and he took flight...
Those who have truly decided to serve the Lord God should practice the remembrance of God and uninterrupted prayer to Jesus Christ, mentally saying: Lord Jesus Christ, Son of God, have mercy on me, a sinner.
One should nourish the soul with the word of God: for the word of God, as St. Gregory the Theologian says, is angelic bread, by which are nourished souls who hunger for God. Most of all, one should occupy oneself with reading the New Testament and the Psalter, which one should do standing up. From this there occurs an enlightenment in the mind, which is in the mind, which is changed by a Divine change.
Suppose you have ordered yourself not to eat fish; you will find that the enemy continually makes you long to eat it. You are filled with an uncontrollable desire for the thing that is forbidden. In this way you can see how Adam's fall typifies what happens to all of us. Because he was told not to eat from a particular tree, he felt irresistibly attracted to the one thing that was forbidden him.
If the base of a felled tree that has grown old in the earth and rock ‘will bud at the scent of water . . . like a young plant’ (Job 14:9), it is also possible for us to be awakened by the power of the Holy Spirit and to flower with the incorruptibility that is ours by nature, bearing fruit like a young plant, even though we have fallen into sin.
A single word made the thief pure and holy, despite all his previous crimes, and brought him into paradise (cf. Luke 23:42-43). A single ill-advised word prevented Moses from entering the promised land (cf. Num. 20:12). We should not suppose, then, that garrulity is only a minor disease. Lovers of slander and gossip shut themselves out of the kingdom of heaven.
Let us go forward with the heart completely attentive and the soul fully conscious. For if attentiveness and prayer are daily joined together, they become like Elias' fire-bearing chariot, raising us to heaven. What do I mean? A spiritual heaven, with sun, moon and stars, is formed in the blessed heart of one who has reach a state of watchfulness, or who strives to attain it.
Thus should we weep for the forgiveness of our sins. The words of the bearer of the purple should convince us of this: 'Going they went and wept, casting their seed; but coming they shall come with joyfulness, carrying their sheaves (Ps. 125:6);' as well as the words of St. Isaac the Syrian: Moisten your cheeks with the tears of your eyes, that the Holy Spirit may abide in you, and cleanse the filth of your malice. Move your lord with your tears, that He may help you.
Reprimand without feeding thine own self-love, considering whether thou wouldst be able to bear what thou demandest of another... It is of greater benefit for the soul to acknowledge itself to be guilty of everything and the last of all, than to resort to self-justification, which hath its origin in pride: God opposeth the prideful, but giveth grace unto the humble.
Pray before your body takes rest on your bed... If you are tempted, make the Sign (of the Cross) on your forehead reverently… for this is a known and tested weapon against the Devil.
