As too many sticks often choke a fire and put it out, while making a lot of smoke, so excessive sorrow often makes the soul smoky and dark, and dries the stream of tears.
Worldly thoughts and material concerns blind the mind, or eye of the soul, like a cloth that covers the physical eyes; so long as we are not free of them, we cannot see.
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.
Sleep is a particular state of nature, an image of death, inactivity of the senses. Sleep is one, but, like desire, its sources and occasions are many; that is to say, it comes from nature, from food, from demons, or perhaps, sometimes, from extreme and prolonged fasting, through which the flesh is weakened and at last longs for the consolation of sleep.
The deadly wound consists of every sin that is not repented and confessed, and of falling into despair. This depends on our choice and will. If we do not yield ourselves to the pit of carelessness and despair the devils cannot prevail over us. Even when we have been wounded, if we so wish we may through fervent penitence become more courageous and skillful fighters.
Mourning has a twofold action: like water tears extinguish all the fire of passions and wash the soul clean of their foulness; and, again, through the presence of the Holy Spirit, it is like fire bringing life, warming the heart, and inciting it to love and desire God.
No man, wise in his own opinion, because he has studied all the sciences and is learned in external wisdom, will ever penetrate God's mysteries or see them unless he first humbles himself and becomes foolish in his heart, repudiating his self-opinion together with his acquirements of learning. For a man who acts thus and follows with undaunted faith those who are wise in things Divine, is guided by them and with them enters into the city of the living God, and, taught and enlightened by the Holy Spirit, sees and knows things which no one else can see or know. Thus he becomes taught of God.
Our holy fathers have renounced all other spiritual work and concentrated wholly on this one doing, that is, on guarding the heart, convinced that, through this practice, they would easily attain every other virtue, whereas without it not a single virtue can be firmly established.
Where poverty of spirit is perceived, there is also the sorrow that is full of joy. There are the everflowing tears that purify the soul that loved these things and cause it to be completely filled with light. By these means the soul looks upward and recognizes its Master.
Our good Redeemer, by speedily granting what is asked, draws to His love those who are grateful. But He keeps ungrateful souls praying a long time before Him, hungering and thirsting for what they want, since a badly trained dog rushes off as soon as it is given bread and leaves the giver behind.
Demons often transform themselves into angels of light and take the form of martyrs, and make it appear to us during sleep that we are in communication with them. Then, when we wake up, they plunge us into unholy joy and conceit. But you can detect their deceit by this very fact. For angels reveal torments, judgments and separations; and when we wake up we find that we are trembling and sad. As soon as we begin to believe the demons in dreams, then they make sport of us when we are awake too. He who believes in dreams is completely inexperienced. 'But he who distrusts all dreams is a wise man. Only believe dreams that warn you of torments and judgments. But if despair afflicts you, then such dreams are also from demons.
Do not be surprised that you fall every day; do not give up, but stand your ground courageously. And assuredly, the angel who guards you will honor your patience.