According to the degree to which the intellect is stripped of the passions, the Holy Spirit initiates the intellect into the mysteries of the age to be.
One must train oneself in generous patience, so as to endure without complaint all that happens to us. We will possess patience when we accept everything that happens to us, both what is joyful and what is sad, without distinction, as from the hand of God.
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.
In patience is the assembly of all the virtues by which our souls are saved, as St. Ephraim says: He who acquires patience touches on every virtue; for he rejoices in sorrows, is well tested in misfortunes, is glad in perils, is ready for obedience, is filled with love, gives praise when provoked, is humble when reproached, is unwavering in misfortunes.