Cultivate patience. Patience is a heavenly gift, a gift from the Heavenly Father... With patience, and love for your fellow men, you become a victor in life's continual trials.
When tested by some trial you should try to find out not why or through whom it came, but only how to endure it gratefully, without distress or rancor.
The most important thing during illness is to offer to God patience and thanksgiving for His merciful visitations. Sickness purifies sins and gives one time to meditate on the past.
Most people desire and seek after prosperity in this life, and they strive to avoid sorrows. While that seems very good and pleasant, constant prosperity and good fortune do a person harm. He falls into a variety of passions and sins, and angers the Lord, while those who live a life of sorrow come closer to the Lord and more readily attain unto salvation, for the Lord called the life of happiness the broad path. The wide gates and the broad way lead to destruction, and many there be who take that way (Matthew 7:13). It is the narrow way and the strait gate which lead to life eternal, and few there be who find it (Matthew 7:14). Thus, according to His love for us, seeing the possible benefit [of sorrows] to those who are worthy, the Lord moves many off the broad road and puts them on the narrow, sorrowful path, so that in [their] patient endurance of sickness and sorrow, He might effect their salvation and grant them life eternal.
Faith is truly a gift, gained for us through Christ's advent. But this does not abolish our freedom or responsibility. God desires of us not only faith but action too.
In Christianity truth is not a philosophical concept nor is it a theory, a teaching, or a system, but rather, it is the living theanthropic hypostasis - the historical Jesus Christ (John 14:6). Before Christ men could only conjecture about the Truth since they did not possess it. With Christ as the incarnate divine Logos the eternally complete divine Truth enters into the world. For this reason the Gospel says: 'Truth came by Jesus Christ' (John 1:17).
The lives of men are subject to drastic changes. These changes are gradual at times; at others, lightning quick. But even those of us who enjoy long years of opulence and fame can find no consolation, no gladness, unless our heart is illumined by the steady light of peace. It is this peace that we must seek, it is for this peace that we should pray. The peace that our Lord gave to His disciples and to all those who really have faith in him.
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 all in your power not to fall, for the strong athlete should not fall. But if you do fall, get up again at once and continue the contest. Even if you fall a thousand times because of the withdrawal of God's grace, rise up again each time, and keep on doing this until the day of your death. For it is written, 'If a righteous man falls down seven times' - that is, repeatedly throughout his life - 'seven times shall he rise again' [Prov. 24:16].
A great effort and much toil are needed in prayer before we can reach a state in which our mind is no longer troubled, and so attain the inward heaven of the heart where Christ dwells. As St. Paul says, 'Do you not realize that Christ dwells within you, unless you are worthless?' (cf. 2 Cor. 13:5).
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.
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.
Not one of us can boast of having acquired humility: our actions, the whole of our life, prove the contrary. And where there is a lack of humility, pride is always present. Where light is wanting, darkness reigns.