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.
Love is the Kingdom, which the Lord mystically promised His disciples to eat in His Kingdom. For when we hear Him say, 'You shall eat and drink at the table of My Kingdom,' what do we suppose we shall eat, if not love? Love is sufficient to nourish a man instead of food and drink. This is the wine 'which makes glad the heart of man.' Blessed is he who partakes of this wine! Licentious men have drunk this wine and felt shame; sinners have drunk it and have forgotten the pathways of stumbling; drunkards have drunk this wine and became firm in virtue; the rich have drunk it and desired poverty; the poor have drunk it and been enriched with hope; the sick have drunk it and become strong; the unlearned have taken it and been made wise.
God rests in holy places; that is (in) the Theotokos and all the Saints. These are they who have become likenesses of God as far as it is possible, since they have chosen to cooperate with divine election. Therefore, God dwells in them.
Read often and insatiably the books of the teachers of the Church on divine providence, for they lead the mind to discern the order in God’s creatures and His actions, give it strength, and by their subtleness they prepare it to acquire luminous intuitions and guide it in purity toward understanding of God’s creatures. Read also the Gospels, which God ordained for knowledge for the whole world, that you may find provisions for your journey in the might of God’s providence for every generation, and that your intellect may plunge deeply into wonder at Him. Such reading furthers your aim. Let your reading be done in a stillness which nothing disturbs; be free of all concern for the body and the turmoil of affairs, so that through the sweet understanding which surpasses all the senses you may savor that most sweet taste in your soul which she perceives in herself because of her constant intercourse with these things.
As it is not possible to cross over the great ocean without a ship, so no one can attain to love without fear. The fetid sea, which lies between us and the noetic paradise, we may cross by the boat of repentance, whose oarsmen are those of fear. But if fear's oarsmen do not pilot the ship of repentance whereby we cross over the sea of this world to God, we shall be drowned in the fetid abyss. Repentance is the ship and fear is the pilot; love is the divine haven.
Fasting is an ordinance of the Church, obliging the Christian to observe it on specific days. Concerning fasting, our Savior teaches: 'When thou fastest, anoint thine head, and wash thy face; that thou appear not unto men to fast, but unto thy Father Who is in secret: and thy Father, Who seeth in secret, shall reward thee openly.' From what the Savior teaches we learn (a) that fasting is pleasing to God, and (b) that he who fasts for the uplifting of his mind and heart towards God shall be rewarded by God, Who is a most liberal bestower of Divine gifts, for his devotion. In the New Testament fasting is recommended as a means of preparing the mind and the heart for divine worship, for long prayer, for rising from the earthly, and for spiritualization.
As soon as a man becomes humble, mercy is not slow to envelop him. Then the heart is aware of God’s help, and acquires a certain power of assurance (in God) which arises in it. And when a man is aware that God’s help is actually assisting him, his heart becomes filled with faith in very truth.
The key to Divine gifts is given to the heart by love of neighbor, and, in proportion to the heart's freedom from the bonds of the flesh, the door of knowledge begins to open before it.
The fear of God is the beginning of virtue, and it is said to be the offspring of faith. It is sown in the heart when a man withdraws his mind from the world’s distraction so as to confine its wandering thoughts within the ruminations of reflection upon the restitution to come.
Faith and love which are gifts of the Holy Spirit are such great and powerful means that a person who has them can easily, and with joy and consolation, go the way Jesus Christ went. Besides this, the Holy Spirit gives man the power to resist the delusions of the world so that although he makes use of earthly good, yet he uses them as a temporary visitor, without attaching his heart to them. But a man who has not got the Holy Spirit, despite all his learning and prudence, is always more or less a slave and worshipper of the world.
Whenever in your path you find unchanging peace, beware: you are very far from the divine paths trodden by the weary feet of the saints. For as long as you are journeying in the way to the city of the Kingdom and are drawing near the city of God, this will be a sign for you: the strength of the temptations that you encounter. And the nearer you draw close and progress, the more temptations will multiply against you.