Do not rail against anyone, but rather say ‘God knows each one.’ Do not agree with him who slanders, do not rejoice at his slander and do not hate him who slanders his neighbor. This is what it means not to judge.
Even if a person’s sin is not only obvious, but very grievous and comes from a hardened and unrepentant heart, do not condemn him, but raise your eyes to the wondrous and incomprehensible judgments of God; then you will see that many people, formerly full of iniquity, later repented and reached a high degree of sanctity, and that, on the other hand, others, who were on a high level of perfection, fell into a deep abyss. Take care, lest you also suffer this calamity through judging others.
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.
When we judge our brother, we censure ourselves in a great sin. When therefore, we shield our brother, God will also shield us from great sins. When we uncover our brother, we drive off the grace of God from over us and we are given over to fall into the same things, so that we learn that we are all weak and the grace of God carries us. Whoever guards his tongue, that one guards his soul from great sins and falls.
Since the enemy watches you constantly, waiting for an opportunity to sow evil in you, be doubly watchful over yourself, lest you fall in the nets spread for you. As soon as he shows you some fault in your neighbor, hasten to repel this thought, lest it take root in you and grow. Cast it out, so that no trace is left in you, and replace it by the thought of the good qualities you know your neighbor to possess, or of those people generally should have. If you still feel the impulse to pass judgment, add to this the truth that you are given no authority for this and that the moment you assume this authority you thereby make yourself worthy of judgment and condemnation, not before powerless men, but before God, the all-powerful Judge of all.
Wherefore a man can know nothing about the judgments of God. He alone is the One Who takes account of all and is able to judge the hearts of each one of us, as He alone is our Master. Truly it happens that a man may do a certain thing (which seems to be wrong) out of simplicity, and there may be something about it which makes more amends to God than your whole life; how are you going to sit in judgment and constrict your own soul? And should it happen that he has fallen away, how do you know how much and how well he fought, how much blood he sweated before he did it? Perhaps so little fault can be found in him that God can look on his action as if it were just, for God looks on his labor and all the struggle he had before he did it, and has pity on him. And you know this, and what God has spared him for, are you going to condemn him for, and ruin your own soul? And how do you know what tears he has shed about it before God? You may well know about the sin, but you do not know about the repentance.
The Lord’s most important commandments are 'Judge not, and ye shall not be judged; condemn not, and ye shall not be condemned; forgive, and ye shall be forgiven.' Moreover, those desirous of salvation should always keep in mind the words of St. Peter Damascene, that creation takes place between fear and hope.
One must train oneself in self-reproach, that is, always accuse oneself & not others in one’s mind, reproach oneself and not others, and with a severe distrust of oneself accuse oneself of the failings which are covered up by our self-love, accuse ourself of our inclinations to sin. He who has self-reproach has peace, writes Abba Dorotheos, & will never be disturbed. If to such a one there should occur an illness, a wrong, a vexation, or some similar misfortune, he ascribes everything to his own sins & thanks God. If such a one is punished or reprimanded by the superior, he accepts all this as good & accepts every severe word against himself without murmuring or talking back, as the judgment of God.
Let him judge of another’s sin who has not on his conscience that which condemns himself. Let him judge who does not himself do what he judges must be punished in another; lest while judging the other he passes sentence upon himself. Let him give judgment on another’s sin who is not led to deliver it by any hate, by dislike, or foolish levity.
Some fast, live as solitaries without possessions, and pray that God will curb their nature; yet in spite of this, they allow themselves to slander, to reproach and judge their neighbors and ridicule them - and so the Divine help departs from them. They are left to themselves and are unable to find strength needed to counteract our nature's sinful suggestions. In a certain cenobitic monastery, there lived a hermit whose name was Timothy. One of the brethren in the cenobium became subject to temptation. When the abbot heard about this, he asked Timothy how the fallen brother should be treated. The hermit advised him that the seduced one should be expelled. And when they had sent him away, the fallen brother's temptation fell upon Timothy, so that he was in peril. Timothy began tearfully to groan for help and mercy from God. A voice came to him, 'Timothy, know that I have sent this temptation to you, because you disdained your brother in his hour of temptation.' One must deal with the members of Christ - Christians - with great care and circumspection. One must actually suffer with them in their weakness, cutting off only those who show no hope for restored health, lest they infect others with their ailments.
Let us strive with all of our power never to put our trust in our own conjectures. For nothing separates us so completely from God or prevents us from noticing our own wrong doing or makes us busy about what does not concern us, as this. No good comes from it but only troubles without number and they leave us no time to acquire the fear of God. Should worthless suspicions germinate in our minds, let us turn them into charitable thoughts and they will not harm us. For entertaining suspicions is wrong and it never allows the mind to be at peace.
Do not regard the feelings of a person who speaks to you about his neighbor disparagingly, but rather say to him: 'Stop, brother! I fall into graver sins every day, so how can I criticize him?' In this way you will achieve two things: you will heal yourself and your neighbor with one plaster. This is one of the shortest ways to the forgiveness of sins; I mean, not to judge. 'Judge not, and ye shall not be judged,' (Luke 6:37).
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).
As for uprooting your passions, begin with self-reproach and with awareness of your own weaknesses; and consider yourself to be deserving of afflictions.