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.
Just as our Lord is solicitous about our salvation, so too the murderer of men, the devil, strives to lead a man into despair... Judas the betrayer was fainthearted and unskilled in battle, and so the enemy, seeing his despair, attacked him and forced him to hang himself; but Peter, a firm rock, when he fell into great sin, like one skilled in battle did not despair nor lose heart, but shed bitter tears from a burning heart, and the enemy, seeing these tears, his eyes scorched as by fire, fled far from him wailing in pain.
'Then the devil left Him, and angels came and ministered to Him' (Matthew 4:11). It does not say that the angels were with our Lord during the actual time when He was being tempted. In the same way, when we are being tempted, God's angels for a time withdraw a little. Then, after the departure of those tempting us, they come and minister to us with divine intellections, giving us support, illumination, compunction, encouragement, patient endurance, joyfulness, and everything that saves and strengthens and renews our exhausted soul. As Nathaniel was told, 'You will see the angels ascending and descending upon the Son of man' (John 1:51); in other words, the ministry and assistance of the angels will be given generously to mankind.
One must endeavor to read through the writings of the Fathers, and strive as much as possible, according to one’s strength, to fulfill what they teach, and in this fashion, little by little ascend from the ascetic life to the perfection of the contemplative.
When we fervently remember God, we feel divine longing well up within us from the depths of our heart. The evil spirits invade and lurk in the bodily senses, acting through the compliancy of the flesh upon those still immature in soul. According to the Apostle, our intellect always delights in the laws of the Spirit (cf. Rom. 7:22), while the organs of the flesh allow themselves to be seduced by enticing pleasures. Furthermore, in those who are advancing in spiritual knowledge, grace brings an ineffable joy to their body through the perceptive faculty of the intellect. But the demons capture the soul by violence through the bodily senses, especially when they find us faint-hearted in pursuing the spiritual path. They are, indeed, murderers provoking the soul to what it does not want.
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.
Those who have truly decided to serve the Lord God must train themselves in the remembrance of God and in unceasing prayer to Jesus Christ, saying mentally: 'Lord Jesus Christ, Son of God, have mercy on me, a sinner.' Through such activity, and by guarding oneself from distraction, and with the preservation of peace in one's conscience, it is possible to draw near to God and to be united with Him. For, according to the words of St. Isaac the Syrian, 'Except for unceasing prayer we cannot draw near to God.'
One must by every means strive to preserve peace of soul and not be disturbed by offenses from others; for this one must in every way strive to restrain anger and by means of attentiveness to keep the mind and heart from improper feelings. And therefore we must bear offenses from others with equanimity and accustom ourselves to such a disposition of spirit that these offenses seem to concern not us, but others. Such a practice can give quietness to the human heart and make it as dwelling for God Himself.
One must by every means strive to preserve peace of soul and not be disturbed by offenses from others; for this one must in every way strive to restrain anger and by means of attentiveness to keep the mind and heart from improper feelings. And therefore we must bear offenses from others with equanimity and accustom ourselves to such a disposition of spirit that these offenses seem to concern not us, but others. Such a practice can give quietness to the human heart and make it as a dwelling for God Himself.
That is why the Mother of God is called the ‘Scourge of Demons,’ for it is not possible for a devil to destroy a man so long as the man himself does not refrain from running to the help of the Mother of God.
When the door of steam baths is continually left open, the heat inside rapidly escapes through it; likewise the soul in its desire to say many things, dissipates the remembrance of God through the door of speech, even though everything it says may be good... Ideas of value always shun verbosity, being foreign to confusion and fantasy. Timely silence, then, is precious, for it is nothing less than the mother of the wisest thoughts.
The man who does not humble himself and does not cleanse his heart from evil desires fasts in vain. He may eat nothing at all, but it will be to no avail if there is evil inside him. He must first cleanse himself from the evil within in order to receive the Lord.
To those who are just beginning to long for holiness, the path of virtue seems very rough and forbidding. It appears like this, not because it really is difficult, but because our human nature from the womb is accustomed to the wide roads of sensual pleasure. But those who have traveled more than half its length find the path of virtue smooth and easy. For when a bad habit has been subjected to a good one through the energy of grace it is destroyed along with the remembrance of mindless pleasures; and thereafter the soul gladly journeys on all the ways of virtue. At the beginning of the struggle, therefore, the holy commandments of God must be fulfilled with a certain forcefulness of will (cf. Matt. 11:12); then the Lord, seeing our intention and labor, will grant us readiness of will and gladness in obeying His purpose. For 'it is the Lord who makes ready the will' (Prov. 8:35, LXX), so that we always do what is right joyfully. Then shall we truly feel that 'it is God who energizes in you both the willing and the doing of His purpose' (Phil. 2:13).
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.