Grow calm, grow quiet after harmful noise... you will experience a certain movement towards eternity; gradually, like a still, small voice, a thought will come to you as to who you are and what is your end and purpose... this is a sign of the approach of the word of God in your soul.
We ought not to grieve or become irritated at anything because, by frequent vexation and irritability, we form the morally and physically very injurious habit of irritability, whilst by bearing opposition with equanimity we form the good and useful habit of enduring everything calmly and patiently.
One should always have at home enough Theophany water to last the whole year, and make use of it at every need: in cases of illness, leaving on a journey, whenever one is upset, students prior to examinations, etc. People who drink a little Holy Water daily, before eating any kind of food, do well. It strengthens the powers of our soul - if it is done with prayer and reverence, and one does not merely expect a mechanical result from it.
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.
The moral character and moral value of man's personality depends most of all on the direction and strength of the will. Of course, everyone understands that for a Christian it is necessary to have first, a strong and decisive will, and second, a will which is firmly directed toward the good of his neighbor, toward the side of good and not evil. How is one to develop a strong will? The answer is simple: above all through the exercise of the will. To do this, as with bodily exercise, it is necessary to begin slowly, little by little. However, having begun to exercise one's will in anything ( e.g., in a constant struggle with one's sinful habits or whims) this work on oneself must never cease. Moreover, a Christian who wishes to strengthen his will, his character, must from the very beginning avoid all dissipation, disorder and inconsistency of behavior. Otherwise, he will be a person without character, unreliable, a reed shaking in the wind, as we read in Holy Scripture.
No one can be saved without the renunciation of his will, even though he might struggle fervently, for our will and our manner are like a bronze wall between us and God.
