If you want cure your soul, you need four things. The first is to forgive your enemies. The second is to confess thoroughly. The third is to blame yourself. The fourth is to resolve to sin no more. If we wish to be saved, we must always blame ourselves and not attribute our wrong acts to others. And God, Who is most compassionate, will forgive us.
St. Paul says: 'The person engaged in spiritual warfare exercises self control in all things' (I Cor. 9:25). Aware of all that is said in divine Scripture, let us lead our life with self-control, especially in regard to food.
God seeks nothing else from us men except that we do not sin; this alone. But this is not a work of law; it is rather a careful guarding of the image and dignity from above. In these things, affirmed in our nature and bearing the radiant garment of the Spirit, we shall abide in God and He in us. We shall be called good, and sons of God by adoption, marked in the light of our knowledge of God.
You ask for some way of completely eradicating irritability. The inclination to irritability is given us to use against sin, and we were never meant to use it against our fellow men. When we do, we act contrary to our true nature.
Pray simply. Do not expect to find in your heart any remarkable gift of prayer. Consider yourself unworthy of it. Then you will find peace. Use the empty cold dryness of your prayer as food for your humility. Repeat constantly: I am not worthy; Lord, I am not worthy! But say it calmly; without agitation.
Do not attempt to assess the quality of your prayer. God alone can judge its value. To us, our own prayer must always appear so poor an effort, so inadequate an achievement, that the cry of the publican spontaneously rises from our lips.
Have you realized that the world and worldly cares do not hinder in fulfilling God's commandments, when there is zeal and attention? That silence and retirement from the world are useless, if laziness and negligence prevail?
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.
But when the Holy Spirit dwells in the heart of a person, He shows him all his inner poverty and weakness, and the corruption of his heart and soul, and his separation from God; and with all his virtues and righteousness. He shows him his sins, his sloth and indifference regarding the salvation and good of people his self-seeking in his apparently most disinterested virtues, his coarse selfishness even where he does not suspect it. To be brief, the Holy Spirit shows him everything as it really is. Then a person begins to have true humility, begins to lose hope in his own powers and virtues, regards himself as the worst of men. And when a person humbles himself before Jesus Christ Who alone is Holy in the glory of God the Father, he begins to repent truly, and resolves never again to sin but to live more carefully. And if he really has some virtues, then he sees clearly that he practiced and practices them only with the help of God, and therefore he begins to put his trust only in God.