What else is so dear to God and welcome as a contrite and humble heart, and pride laid low in a spirit of humility? It is in such a condition of soul that God Himself comes to dwell and make His rest, and that every machination of the devil remains ineffective.
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.
In truth, whatever we may suffer, we suffer it because of our sins. If the saints suffered, they suffered for God's name or to demonstrate their virtue for the benefit of many or to gain greater reward from God. As for us wretches, how can we say this? We sin like this daily and in seeking to satisfy our passion, we abandoned the right path, which the Fathers spoke about, that of self-accusation. Each one of us follows the wrong path, tries on every occasion to put the case against his brother and throw the burden of responsibility upon him. Each one of us is negligent and keeps nothing, but demands that our neighbor keeps the commandments.
In answer to your question as to what constitutes a happy life, whether splendor, fame and wealth, or a quiet, peaceful, family life, I will say that I agree with the latter, but will add the following: A life lived in humility and with an irreproachable conscience brings peace, tranquility, and true happiness. But wealth, honor, glory and exalted position often serve as the cause of a multitude of sins, and such happiness is not one on which to rely.
Do not be deluded by thoughts that virtue exceeds your powers and is impossible for you; but, inspired by faith, boldly make a beginning, show before God your good will and diligence - and you will see the help He will send you to practice virtue.
You are, I am sure, aware that for you penitence is now no longer limited to disclosing your sins to your confessor, but that you must now bear your sins in mind always, until your heart nearly breaks with their ugly load; and would break, were it not for your firm faith in the mercy of our Lord.
The enemy constantly endeavors to awaken in the abyss of the human heart a great turmoil about trifles. This is one of his tricks to blind our soul to the sun of truth, Christ our Lord, hidden in the heart's core of every one of our neighbors.
'Fear of the Lord is the beginning of wisdom' (Prov. 1:7). For where there is fear, there the commandments are kept, and where the commandments are kept the flesh is purified, together with the cloud that envelops the soul and prevents it from clearly seeing the divine radiance.
Wherever we are and whatever our circumstances, the enemy always tries to prevent us from actively responding to the call. Pray for help. For help that you may never fail to respond. And beware lest, having received help and having done the right deed because of it, you should grow proud and acquire the habit of condemning others, in the secret chambers of your heart. Beware! For this would make all the fruits of your good works wither.
Take care never to receive Communion while you have anything against anyone, even if this is only a hostile thought. Not until you have brought about reconciliation through repentance should you communicate, [receive the Mysteries]. But you will learn this, too, through prayer.
Our achievements must never loom large in our eyes; only our failures. But this must never lead us to despondency - the constant temptation - only to humility.
Our Lord was pleased to assume the likeness of every poor man and compared Himself to every poor man in order that no man who believes in Him should exalt himself over his brother, but, seeing his Lord in his brother, should consider himself less and worse than his brother, just as he is less than his Creator; and should take the poor man in and honor him, and be ready to exhaust all means to helping him, just as our Lord Jesus Christ exhausted His blood for our salvation.
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.