A man who falls into sin is different from the way he was created. He is different, because he changes by his own actions the way he was meant to be. Man renounces himself when he becomes a different person through repentance. He leaves a corrupted man, which he had become through sin, and becomes such as he once was created, through mercy.
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.
The late Athonite Father Tikhon used to say: The prayer, 'Lord Jesus have mercy on us' is worth one hundred drachmas, but 'Glory to God' is word one thousand. Glorifying God is more valuable than anything else, because in the first instance, people often say the Jesus Prayer when needing something; but when one glorifies God in the midst of suffering, it is an ascesis.
Was there ever anyone of any breeding who dared to speak the name of Holy Mary, and being questioned, did not immediately add, 'the Virgin'? For by such added names the positive proofs of merit are apparent... And to the Holy Mary, Virgin is invariably added, for that Holy Woman remains undefiled.
We should not miss any chance to us to say the Jesus Prayer. We must not let our mind wander in vain things. In saying the Jesus Prayer one's mind finds rest and joy. It is like small children who for the whole day run around, shouting and playing and hitting each other. But the one thing that gives them rest and great joy is when at night they find themselves in their mother's arms. This way also one's mind instead of being scattered about, out to be devoted to mental prayer.
BROTHER: Behold, through what have the men of old triumphed? OLD MAN: Through the fervor of their supernatural love, and through the death of the corruptible man, and through the contempt for pride, and through the abatement of the belly, and through the fear of the judgement, and through the promise of certainty; through the desire for these glorious things the fathers have acquired in the soul the spiritual body.
One time St. Nicodemos, on a feast day, was walking toward the Great Lavra (on Mt Athos). On his way he came across a kellion where he spent the night. At midnight he saw an elder and his accompanying monks entering the church. He secretly went in also, and there he saw the elder and his subordinate monks uttering the Jesus Prayer ('Lord Jesus Christ, Son of God, have mercy on me'), sometimes in a kneeling position, sometimes standing up. And at the time of the Holy Communion, he saw all their faces shining only a little less dimly than the sun.
During the time of one’s confession not only the person who makes his confession is judged, but the confessor as well. In the past, confessors were practical. They did not judge on the basis of the seriousness of a transgression, but rather on the intent. They did not concentrate so much on the sins being confessed as on thinking of how to treat the repentant person’s soul.
It is as necessary for a man to say the Jesus Prayer as it is for a ship in danger to send out steadily the S.O.S. signal: Lord Jesus Christ have mercy on me.
BROTHER: Who is the true monk? OLD MAN: He who makes his word manifest in deeds, and bears his passion with patient endurance; with such a man life is found, and the knowledge of the spirit dwells in him.