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.
The nature then of Christ's teaching is attested by His own holy statements: that they who wish to arrive at eternal blessedness may understand the steps of ascent to that high happiness. 'Blessed,' He saith, 'are the poor in spirit, for theirs is the kingdom of heaven.' It would perhaps be doubtful what poor He was speaking of, if in saying 'blessed are the poor' He had added nothing which would explain the sort of poor: and then that poverty by itself would appear sufficient to win the kingdom of heaven which many suffer from hard and heavy necessity. But when He says 'blessed are the poor in spirit,' He shows that the kingdom of heaven must be assigned to those who are recommended by the humility of their spirits rather than by the smallness of their means.
Since the angels and souls are incorporeal beings, they are not in a particular place, yet neither are they everywhere. They do not sustain all things, but themselves depend on Him Who sustains them. Hence they, too, are in Him Who sustains and embraces all things, and they are appropriately delimited by Him. The soul, since it sustains the body with which it is created, is everywhere in the body, although not in the sense of being located in a place or encompassed; but it itself sustains, encompasses and quickens the body, by virtue of the fact that it is in God's image.
Even a pious person is not immune to spiritual sickness if he does not have a wise guide -- either a living person or a spiritual writer. This sickness is called prelest, or spiritual delusion, imagining oneself to be near to God and to the realm of the divine and supernatural. Even zealous ascetics in monasteries are sometimes subject to this delusion, but of course, laymen who are zealous in external struggles (podvigi) undergo it much more frequently. Surpassing their acquaintances in struggles of prayer and fasting, they imagine that they are seers of divine visions, or at least of dreams inspired by grace. In every event of their lives, they see special intentional directions from God or their guardian angel. And then they start imagining that they are God's elect, and often try to foretell the future. The Holy Fathers armed themselves against nothing so fiercely as against this sickness -- prelest.
Blessed are those who acquire the habit of this heavenly practice (unceasing prayer in the name of Jesus), for by it they overcome every temptation of the evil demons, as David overcame the proud Goliath. It extinguishes the unruly lusts of the flesh, as the three men extinguished the flames of the furnace. This practice of inner prayer tames passions as Daniel tamed the wild beasts. By it the dew of the Holy Spirit is brought down upon the heart, as Elijah brought down rain on Mount Carmel.
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.
Compunction comes when you consider how much you have grieved God Who is so good, so sweet, so merciful, so kind, and entirely full of love; Who was crucified and suffered everything for us. When you meditate on these things and other things the Lord has suffered, they bring compunction.
This mental prayer is the light which illumines man’s soul and inflames his heart with the fire of love of God. It is the chain linking God with man and man with God. Oh the incomparable blessing of mental prayer! It allows a man constantly to converse with God. Oh truly wonderful and more than wonderful – to be with one’s body among men while in one’s mind conversing with God. Angels have no physical voice, but mentally never cease to sing glory to God. This is their sole occupation and all their life is dedicated to this.
There is nothing more efficacious against the wiles of the devil, dearly beloved, than the kindness of forgiveness, and the bountifulness in charity, by means of which sin is either avoided or overcome.
For forgiveness of sins is most efficaciously prayed for with almsgiving and fasting, and supplications that are winged by such aids mount swiftly to God’s ears; since it is written, 'the merciful man doeth good to his own soul' (Prov. xi. 17), and nothing is so much a man’s own as that which he spends on his neighbor. For that part of his material possessions with which he ministers to the needy, is transformed into eternal riches, and such wealth is begotten of this bountifulness as can never be diminished or in any way destroyed, for 'blessed are the merciful, for God shall have mercy on them' (Matt. v.7), and He himself shall be their chief Reward, who is the Model of His own command.
For those who bear them with faith, misfortunes serve to correct their sins, to exercise and test them, to lead them to abandon the wretchedness of this life, and to encourage them to long fervently and seek constantly for everlasting adoption as sons and redemption, the truly new life and blessedness.
He who wishes to tear up the account of his sins and to be inscribed in the Divine book of the saved, can find for this purpose no better means than obedience.
Truly wretched and three times miserable is the soul that has left the world and dedicated itself to God but has not lived in a manner worthy of its promise. Then, brothers, let us not allow this age, which is short and contemptible and passes like a shadow, to steal that blessed and immortal life away from us.
Patient endurance is the fruit of love, for 'love patiently endures all things' (I Cor. 13:7), and teaches us to achieve such endurance by forcing ourselves so that through patience we may attain love...
We should bear in mind the fact that just as the earth cannot yield worthwhile fruit without labor, so the soul cannot acquire anything which pleases God or leads to salvation without spiritual struggles.
Apostolic teaching, Beloved, exhorts us that we put off the old man with his deeds (Eph. iv. 22; Col. iii. 9), and renew ourselves from day to day by a holy manner of life. For if we are the temple of God, and if the Holy Spirit is a Dweller in our souls, as the Apostle says: You are the temple of the living God (II Cor. vi. 16); we must then strive with all vigilance that the dwelling of our heart be not unworthy of so great a Guest.
Let no one think, my brother-Christians, that it is the duty only of priests and monks to pray without ceasing, and not of laymen. No, no; it is the duty of all of us Christians to remain always in prayer. For look what the most holy Patriarch of Constantinople, Philotheus, writes in his life of St. Gregory of Thessalonica. This saint had a beloved friend by the name of Job, a very simple but most virtuous man. Once, while conversing with him, His Eminence said of prayer that every Christian in general should strive to pray always, and to pray without ceasing, as Apostle Paul commands all Christians, 'Pray without ceasing' (I Thessalonians 5:17), and as the prophet David says of himself, although he was a king and had to concern himself with his whole kingdom: 'I foresaw the Lord always before my face' (Psalms 15:8), that is, in my prayer I always mentally see the Lord before me. Gregory the Theologian also teaches all Christians to say God’s name in prayer more often than to breathe. So, my Christian brethren, I too implore you, together also with St. Chrysostom, for the sake of saving your souls, do not neglect the practice of this prayer. Imitate those I have mentioned and follow in their footsteps as far as you can.