The humility which in due time and by God's grace, after many struggles and tears, is given by heaven to those who seek it is something incompararably stronger and higher than the sense of abasement felt by those who have lapsed from holiness. This higher humility is granted only to those who have attained true perfection and are no longer under the sway of sin.
If you refuse to accept suffering and dishonor, do not claim to be in a state of repentance because of your other virtues. For self-esteem and insensitivity can serve sin even under the cover of virtue.
Do all in your power not to fall, for the strong athlete should not fall. But if you do fall, get up again at once and continue the contest. Even if you fall a thousand times because of the withdrawal of God's grace, rise up again each time, and keep on doing this until the day of your death. For it is written, 'If a righteous man falls down seven times' - that is, repeatedly throughout his life - 'seven times shall he rise again' [Prov. 24:16].
Peter was first given the keys, but then he was allowed to fall into the sin of denying Christ; and so his pride was humbled by his fall. Do not be surprised, then, if after receiving the keys of spiritual knowledge you fall into various evil thoughts. Glorify our Lord, for He alone is wise: through setbacks of this kind He restrains the presumption that we tend to feel because of our advance in the knowledge of God. Trials and temptations are the reins whereby God in His providence restrains our human arrogance.
Courage does not consist in defeating and oppressing one's neighbor, for this is overbearingness, which oversteps the bounds of courage. Nor again does it consist in fleeing terrified from the trials that come as a result of practicing the virtues; for this is cowardice and falls short of courage. Courage itself consists in persisting in every good work and in overcoming the passions of soul and body. For our struggle is not against flesh and blood, that is, against men, as was the case with the Jews of old, where to conquer other nations was to do the work of God; it is against principalities and powers, that is, against the unseen demons (Ephesians 6:12). He who is victorious conquers spiritually; otherwise he is conquered by the passions. The warfare described in the Old Testament prefigures our spiritual warfare. These two passions of overbearingness and cowardice, though they appear to be opposites, are both caused by weakness. Overbearingness pulls one upwards and is outwardly something startling and frightening, like some powerless bear, while cowardice flees like a chased dog. No one who suffers from either of these two passions puts his trust in the Lord, and therefore he cannot stand firm in battle, whether he is overbearing or cowardly. But the righteous man is as bold as a lion (Proverbs 28:1) in Christ Jesus our Lord, to whom be glory and dominion throughout the ages.
He who chooses maltreatment and dishonor for the sake of truth is walking on the apostolic path; he has taken up the cross and is bound in chains (cf. Mt 16:24). But when he tries to concentrate his attention on the heart without accepting these two, his intellect wanders from the path and he falls into the temptations and snares of the devil.
It is more serious to lose hope than to sin. The traitor Judas was a defeatist, inexperienced in spiritual warfare; as a result he was reduced to despair by the enemy's onslaught, and he went and hanged himself. Peter, on the other hand, was a firm rock: although brought down by a terrible fall, yet because of his experience in spiritual warfare he was not broken by despair, but leaping up he shed bitter tears from a contrite and humiliated heart. And as soon as our enemy saw them, he recoiled as if his eyes had been burnt by searing flames, and he took flight...
Fire makes iron impossible to touch, and likewise frequent prayer renders the intellect more forceful in its warfare with the enemy. That is why the demons strive with all their strength to make us slothful in attentiveness to prayer, for they know that prayer is the intellect's invincible weapon against them.
A single word made the thief pure and holy, despite all his previous crimes, and brought him into paradise (cf. Luke 23:42-43). A single ill-advised word prevented Moses from entering the promised land (cf. Num. 20:12). We should not suppose, then, that garrulity is only a minor disease. Lovers of slander and gossip shut themselves out of the kingdom of heaven.
This prayer should never be absent from you: 'Lord Jesus Christ, Son and Logos of the living God, through the Theotokos and all the Saints, have mercy upon me, Thy sinful and unworthy servant.' (This is the actual Jesus Prayer: 'O LORD JESUS CHRIST, SON OF GOD, HAVE MERCY UPON ME, A SINNER.') Always say this prayer both with your mouth and with your mind, day and night, wherever you may be, whether eating, walking, working, or sitting. Always meditate on it, as it benefits you a great deal, frees you here from every evil, delivers you there from eternal Hell, and renders you worthy of going to Paradise, our heavenly country.
Some people when praised for their virtue are delighted, and attribute this pleasurable feeling of self-esteem to grace. Others when reproved for their sins are pained, and they mistake this beneficial pain for the action of sin.
Sear your loins by abstaining from food, and prove your heart by controlling your speech, and you will succeed in bringing the desiring and incensive powers of your soul into the service of what is noble and good.