He who seeks grace from God must, above all, endure temptations and afflictions no matter how they come. Otherwise, if he becomes indignant and doesn't show enough patience during temptation, neither will grace manifest itself, nor will his virtue be perfected or will he be counted worthy of any spiritual gift.
When said with pain, the prayer gives birth to mourning. Mourning brings tears. Tears in turn give birth to purer prayer. For tears like a fragrant myrrh wash away the filth, and thus the inbreathing of God is cleansed, which like a dove is confined within four walls, as if made of the four elements.... And then, as soon as the walls break down and collapse, the dove immediately flies to the Father whence it came.
The passion of self-esteem is a three-pronged barb heated and forged by the demons out of vanity, presumption and arrogance. Yet those who dwell under the protection of the God of heaven (cf. Ps. 91.1) detect it easily and shatter its prongs, for through their humility they rise above such vices and find repose in the tree of life.
Without temptations, pure souls are not known, virtue does not show, patience is not discernible. Without temptations, it is impossible for the soul to become healthy. They are the cleansing fire which makes the soul pure and bright.
The grace of repentance, which acts in those who struggle, is a patristic inheritance. It is a divine transaction and exchange in which we give dust and receive heaven. We exchange matter for the Spirit. Every drop of sweat, every pain, every ascesis for God is an exchange.
Man's chief aim should be to find God. In finding God, he finds true happiness. The interior prayer we have been discussing [the Prayer of Jesus] leads man to Him. We can never thank God sufficiently for revealing Himself to us. We can never even thank Him enough for the other goods He bestows upon us. God need not have created man: He had hosts of angels. Yet He created man and countless marvelous things for him.