Our holy fathers have renounced all other spiritual work and concentrated wholly on this one doing, that is, on guarding the heart, convinced that, through this practice, they would easily attain every other virtue, whereas without it not a single virtue can be firmly established.
When your brother is disturbed and reacts to what you say to him, control your tongue lest you speak even one word in wrath and do not allow yourself to be arrogant concerning him in your heart but remember that he is your brother, a member of Christ and an image of God, influenced by the common enemy. Be merciful and show pity on him because it is possible that the devil through your wrath, will capture his soul and mortify it in resentment and thus, through your carelessness, the soul for whom Christ died is lost (1 Cor. 5:11).
The guarding of the conscience with regard to one’s neighbor is doing absolutely nothing at all that we know will upset or wound him, either by deed, word, gesture or even a glance. Even a gesture, can wound one’s neighbor. Briefly, man infects his conscience by deliberately doing those things that he knows will provoke his neighbor and will harm and embarrass him. Therefore, to keep one’s conscience and not act in this manner, is what we mean by keeping our conscience towards our neighbor.
It was said of Abba Arsenius that once when he was ill at Scetis, the priest came to take him to church and put him on a bed with a small pillow under his head. Now behold, and old man who was coming to see him, saw him lying on a bed with a little pillow under his head and he was shocked and said, 'Is this really Abba Arsenius, this man lying down like this?' Then the priest took him aside and said to him, 'In the village where you lived, what was your trade?' 'I was a shepherd,' he replied. 'And how did you live?' 'I had a very hard life.' Then the priest said to him, 'And how do you live in your cell now?' The other replied, 'I am more comfortable.' Then the priest said to him, 'Do you see this Abba Arsenius? When he was in the world he was the guardian of the emperor, surrounded by thousands of slaves with golden girdles, all wearing collars of gold and garments of silk. Beneath him were spread rich coverings. While you were in the world as a shepherd you did not enjoy even the comforts you now have, but he no longer enjoys the delicate life he led in the world. So you are comforted while he is afflicted.' At these words, the old man was filled with compunction and prostrated himself saying, 'Father, forgive me, for I have sinned. Truly the way this man follows is the way of truth, for it leads to humility, while mine leads to comfort.' So the old man withdrew, edified.
A man is neither saved nor lost by the place he is in, but is saved or lost by his deeds. Neither a holy place nor a holy state is of use to him who does not fulfill the commandments of the Lord.
It is up to us now to either bury our conscience under the ground, or to have it shine forth and illuminate us if we obey it. When our conscience says to us, 'Do this,' and we treat it with contempt, or it says it again and we refuse, then we are trampling it down, burying it under ground. Thus, it cannot speak to us clearly because of the weight upon it.
It was said of Abba Mark the Egyptian that he lived for thirty years without going out of his cell. The priest used to take Holy Communion to him. But the devil, seeing the remarkable endurance of this man, decided to tempt him, by making him blame the priest. He brought it about that a demoniac went to the old man, under the pretext of asking for prayers. Before anything was said, the possessed man cried out to the old man, 'Your priest smells of sin, do not let him come near you any more.' But Mark, filled with the spirit of God, said to him, 'My son, everyone rids himself of impurity, but you bring it. It is written: ‘Judge not for that you be not judged.’ (Matt. 7:1) However, even if he is a sinner, the Lord will save him, for it is written: ‘Pray for one another that you may be healed.’' (James 5:16) When he had said this and when he had prayed, he drove the devil out of the man and sent him away healed. When the priest came, according to his custom, the old man received him with joy. Seeing the absence of malice in the old man, the good God showed him a marvel. When the priest prepared himself to stand before the holy table, this is what the old man related: 'I saw the angel of the Lord descent from heaven and place his hand on the priest’s head and he became like a pillar of fire. I was filled with wonder at this sight, and I heard a voice saying to me, ‘Man, why are you astonished at this? In truth, if an earthly king does not allow his nobles to stand in his presence in soiled garments, but only arrayed in glory, how much more will the divine power purify the servants of the holy mysteries who stand before the heavenly glory?’' And the noble athlete of Christ, Mark the Egyptian, became great and was judged worthy of this grace because he had not judged the priest.
Once two brethren came to a certain elder whose custom it was not to eat every day. But when he saw the brethren he invited them with joy to dine with him, saying: Fasting has its reward, but he who eats out of charity fulfills two commandments, for he sets aside his own will and he refreshes his hungry brethren.
Believe that dishonors and reproaches are medicines that heal the pride of thy soul, and pray for those who reproach thee, as for true physicians of thy soul, being assured that he who hates dishonor, hates humility, and he who avoids those who grieve him, flees from meekness.