Those who have truly decided to serve the Lord God should practice the remembrance of God and uninterrupted prayer to Jesus Christ, mentally saying: Lord Jesus Christ, Son of God, have mercy on me, a sinner.
The Cross of the Lord was the instrument by which He saved the world after the fall into sin. Through the Cross, He descended with His soul into hell so as to raise up from it the souls who were awaiting Him. By the Cross, Christ opened the doors of paradise which had been closed after our first ancestors had been banished from it. The Cross was sanctified by the Body of Christ which was nailed to it when He gave Himself over to torments and death for the salvation of the world, and it itself was then filled with life-giving power. By the Cross on Golgotha, the prince of this world was cast out (John 12:31) and an end was put to his authority. The weapon by which he was crushed became the sign of Christ's victory.
The head of every good striving and the pinnacle of all corrections is to persevere in prayer, by which we may ever obtain, through entreaty of God, all the other virtues as well. By prayer those who are worthy partake of the sanctity of God and spiritual activity and the union of the mind with the Lord in unutterable love. He who constantly forces himself to endure in prayer is roused by spiritual love to Divine fervor and flaming desire towards God, and he receives, according to his measure, the grace of spiritual, sanctifying perfection.
Anger is by nature designed for waging war with the demons and for struggling with every kind of sinful pleasure. Therefore angels, arousing spiritual pleasure in us and giving us to taste its blessedness, incline us to direct our anger against the demons. But the demons, enticing us towards worldly lusts, make us use anger to fight with men, which is against nature, so that the mind, thus stupefied and darkened, should become a traitor to virtues.
All the pleasers of God are like the angels in their love and devotion. They, just as the angels, waged war against the dark forces, and became strengthened in love of God. All of the prophets of the Old Testament lived in such a struggle. Godlessness prevailed, the Law of God was forgotten. The world persecuted them because they interfered with its sinful life. They hid in the 'depths of the earth.' The world hated them. The prophet Isaiah was sawed in two by a wooden saw, the prophet Jeremiah was trampled in a swamp. And in such surroundings they stood fast in faith and devotion. All righteous ones were sorrowful in the world because they were strangers to the sinful world. All of the apostles suffered in one way or another. Righteous men left for the desert. What made them saints? Suffering? Not suffering alone makes saints, but striving towards God, love of God, and the labor of overcoming obstacles to holiness, which is the fruit of man's labor and the gift of the Holy Spirit.
They asked Abba Macarius, 'How should we pray?' And the old man replied, 'There is no need to speak much in prayer; often stretch out your hands and say, 'Lord, as you will and as you know, have mercy on me.' But if there is war in your soul, add, 'Help me!' and because he knows what we need, he shows mercy on us.'
One of the Fathers said: just as it is impossible for a man to see his face in troubled water, so too the soul, unless it be cleansed of alien thoughts, cannot pray to God in contemplation.
First of all it must be understood that it is the duty of all Christians - especially of those whose calling dedicates them to the spiritual life - to strive always and in every way to be united with God, their creator, lover, benefactor, and their supreme good, by whom and for whom they were created. This is because the center and the final purpose of the soul, which God created, must be God Himself alone, and nothing else - God from whom the soul has received its life and its nature, and for whom it must eternally live. For all visible things on earth which are lovable and desirable - riches, glory, wife, children, in a word everything of this world that is beautiful, sweet, and attractive - belong not to the soul but only to the body, and being temporary, will pass away as quickly as a shadow. But the soul, being eternal by its nature, can attain eternal than all beauty, sweetness, and loveliness, and He is its natural home, whence it came and whither it must return. For as the flesh coming from the earth returns to the earth, so the soul coming from God returns to God and dwells in Him. For the soul was created by God in order to dwell in Him forever; therefore in this temporary life we must diligently seek union with God, in order to be accounted worthy to be with Him and in Him eternally in the future life.
Join to every breath a sober invocation of the name of Jesus and the thought of death with humility. Both these practices bring great profit to the soul.
Unless humility and love, simplicity and goodness regulate our prayer, this prayer - or, rather, this pretence of prayer - cannot profit us at all. And this applies not only to prayer, but to every labor and hardship undertaken for the sake of virtue.