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.
Men who are leading a spiritual life see by the eyes of their heart how the devil lays his snares, how the angels guide us, and how the Lord, in His Sovereign power, allows the temptations, and how he comforts.
Those who have acquired genuine prayer experience an ineffable poverty of the spirit when they stand before the Lord, glorify and praise Him, confess to Him, or present to Him their entreaties. They feel as if they had turned to nothing, as if they did not exist. That is natural. For when he who is in prayer experiences the fullness of the divine presence, of Life Itself, of Life abundant and unfathomable, then his own life strikes him as a tiny drop in comparison to the boundless ocean. That is what the righteous and long-suffering Job felt as he attained the height of spiritual perfection. He felt himself to be dust and ashes; he felt that he was melting and vanishing as does snow when struck by the sun's burning rays (Job 42:6).
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.