Conscience in men is nothing else but the voice of the omnipresent God moving in the hearts of men, as He Who alone Is and has created everything, the Lord knows all as Himself - all the thoughts, desires, intentions, words, and works of men, present, past, and future. However far in front I may let my thoughts, my imagination, run He is there before me and I ever inevitably finish my course in Him, ever having Him as the witness of my ways. 'His eyes are open upon all the ways of the sons of men' (Jer 32:19). 'Whither shall I go from Thy Spirit, or whither shall I flee from Thy presence?' (Ps 139:7).
You describe how bitterly you regret the inefficacy of your prayers. Beware: to wish for consolation or revelation in prayer is a sure sign of pride. Pray humbly, in perfect simplicity, seeking salvation only through forgiveness, & having faith that God will extend to you His mercy - as He did to the publican.
Sear your loins by abstaining from food, and prove your heart by controlling your speech, and you will succeed in bringing the desiring and incensive powers of your soul into the service of what is noble and good.
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.
In order not to be in daily bondage to the passions and the devil, you must set yourself an object to aim at, have this object constantly in view, and endeavor to attain it, conquering all obstacles by the name of the Lord. What is this object? The Kingdom of God, the Divine palace of glory, prepared for believers from the creation of the world. But as this object can only be attained by certain means, it also is necessary to have such means at one's disposal. And what are these means? Faith, hope, and love, especially the last. Believe, hope, and love, especially love, disregarding all obstacles; love God above everything and your neighbor as yourself. If you have not sufficient strength to preserve in your heart these inestimable treasures, fall down more often at the feet of the God of Love. Ask, and it shall be given you; seek and ye shall find; knock and it shall be opened unto you, for He Who has promised is true. Walking, sitting, lying down, conversing, or working, at every time, pray with your whole heart that faith and love may be given to you. You have not yet asked for them as you should ask - fervently and instantly - with the firm purpose of obtaining them. Say now, 'I will begin to do so henceforth.'
If some Christians cannot comprehend our Orthodox faith, its Sacraments, it proves that the minds and hearts of such persons are too impure and passionate to bear its purity and brightness, just as sick eyes cannot bear the light of the sun. This heavenly treasure can only be comprehended by the hearts of those who free their minds and feelings from worldly attachments.
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.
The Church is the sure way to the life eternal; walk in it undeviatingly, hold fast to it, and you will gain the kingdom of heaven; but if you turn aside at the crossways of your own sophistry and unbelief, then you have only yourself to blame, you will go astray and be lost. ‘I am the way, the truth, and the life.’ (John 14:6)
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.
We are told: It is no big deal to eat non-Lenten food during Lent. It is no big deal if you wear expensive beautiful outfits, go to the theater, to parties, to masquerade balls, use beautiful expensive china, furniture, expensive carriages and dashing steeds, amass and hoard things, etc. Yet what is it that turns our heart away from God, away from the Fountain of Life? Because of what do we lose eternal life? Is it not because of gluttony, of expensive clothing like that of the rich man of the Gospel story, is it not because of theaters and masquerades? What turns us hard-hearted toward the poor and even toward our relatives? Is it not our passion for sweets, for satisfying the belly in general, for clothing, for expensive dishes, furniture, carriages, for money and other things? Is it possible to serve God and mammon, to be a friend to the world and a friend to God, to serve Christ and Belial? That is impossible. Why did Adam and Eve lose paradise, why did they fall into sin and death? Was it not because of one evil? Let us attentively consider why we do not care about the salvation of our soul, which cost the Son of God so dearly. Why do we compound sin upon sin, fall endlessly into opposing to God, into a life of vanity? Is it not because of a passion for earthly things and especially for earthly pleasures? What makes our hearts become crude? Why do we become flesh and not spirit, perverting our moral nature? Is it not because of a passion for food, drink, and other earthly comforts? How after this can one say that it does not matter whether you eat non-Lenten food during Lent? The fact that we talk this way is in fact pride, idle thought, disobedience, refusal to submit to God, and separation from Him.
Remember that a good action is always either preceded or followed by temptations. God permits this so that the virtue, exercised in that particular action, may be confirmed, consolidated, steeled.
When God, using our conscience, calls us to righteousness and yet our self-will opposes Him, He respects our freedom and lets our own will be done; but then, alas, our minds grow dull, our will slack, and we commit iniquities without number. On the other hand, the fruits of the spirit are soon granted to them who follow the commandments of Christ our Lord.
Most men not only bear Satan's burden willingly in their hearts, but they become so accustomed to it that they often do not feel it, and even imperceptibly increase it. Sometimes, however, the evil enemy increases his burden tenfold, and then they become terribly despondent and fainthearted, they murmur and blaspheme God's name. The usual means that men... take to drive away their anguish are... entertainments... But such means afterwards increase still more the anguish and weariness of their hearts. If, happily, they turn to God, then the burden is removed from their heart, and they clearly see that previously the heaviest burden was lying on their heart, though frequently they did not feel it.
Our soul is simple as thought, and rapid as thought or lightning. In an instant it can be wounded by sin and become attached to corruptible things; in an instant it can fall away from the love of God and its neighbor through a single unrighteous thought, through a single passionate desire, through a single malevolent thought, and, therefore, we must constantly watch our heart, lest it should incline to words or thoughts of evil, and must ever strive to preserve it in God's simplicity and purity, and in the love of God and its neighbor.
Keep a strict watch against any appearance of pride: it appears imperceptibly, particularly in time of vexation and irritability against others for quite unimportant causes.