A prayer offered while one has any cause to reproach a fellow man is an impure prayer. There is only one whom the praying person may and must reproach, and that is himself. Without self-reproach, your prayer is as worthless as it is while you are reproaching someone else in your heart. Perhaps you ask: How can one learn this? The answer is: One learns it through prayer.
He who wants to cross the spiritual sea is long-suffering, humble, vigilant and self-controlled. If he impetuously embarks on it without these four virtues, he agitates his heart, but cannot cross.
But if you are fearful of becoming self-righteous from working for your own salvation, or afraid of being overcome by spiritual pride, examine yourself and observe that the person who is afraid of becoming self-righteous suffers from blindness. For he does not see how self-righteous he is.
The vain desires of this world separate us from our homeland; love of them and habit clothe our soul as if in a hideous garment. We, traveling on the journey of this life and calling on God to help us, ought to be divesting ourselves of this hideous garment and clothing ourselves in new desires, in a new love of the age to come, and thereby to receive knowledge of how near or how far we are from our heavenly homeland. But it is not possible to do this quickly; rather one must follow the example of sick people, who, wishing the desired (health), do not leave off seeking means to cure themselves.
Those who have sinned must not despair. Let that never be. For we are condemned not for the multitude of evils, but because we do not want to repent...
To the world belong our desires and impulses. enumerates them: Weakness for wealth and for collecting and owning things of different kinds; the urge for physical (sensuous) enjoyment; the longing for honor, which is the root of envy; the desire to conquer and be the deciding factor; pride in the glory of power; the urge to adorn oneself and to be liked; the craving for praise; concern and anxiety for physical well-being. All these are of the world; they combine deceitfully to hold us in heavy bonds. If you wish to free yourself, scrutinize yourself with the help of that list and see clearly what you have to struggle against in order to approach God. For friendship with the world is enmity with God, and whosoever therefore will be a friend of the world is the enemy of God (James 4:4).
The abstinent withdraws from gluttony, the uncovetous from covetousness, the silent from wordiness, the pure from attachment to sensory pleasures, the chaste from fornication, he who is content with what he has from love of money, the meek from agitation (anger), the humble from vanity, the obedient from objection, he who is honest with himself from hypocrisy; equally, he who prays withdraws from despair, the willing pauper from acquisitiveness, he who professes his faith from denying it, the martyr from idolatry – so you see that each virtue, performed even unto death, is nothing but withdrawal from sin; and withdrawal from sin is a natural action, not an action which could be rewarded by the kingdom.
A person standing at an open window hears the sounds from outside; it is impossible not to do so. But he can give the voices his attention or not, as he himself wishes. The praying person is continually beset by a stream of inappropriate thoughts, feelings and mental impressions. To stop this tiresome stream is as impracticable as to stop the air from circulating in an open room. But one can notice them or not. This, say the saints, one learns only through practice.
It took Noah a hundred years to build his ark; log upon log he dragged to the construction. Do as he did; drag log upon log to your construction, patiently, in silence, day after day, and do not inquire about your surroundings. Remember that Noah was the only on in the whole world who 'walked with God' (Gen. 6:9), that is, in prayer. Imagine the crowding, the darkness, the stench, that he had to live in until he could step out into the pure air and build an altar to the Lord. The air and the altar you will find within you, explains St. John Chrysostom, but only after you have willingly gone through the same narrow gate as Noah.