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.
At first it may appear very difficult to you, but be assured, as it were from Almighty God, that this very name of our Lord Jesus Christ, constantly invoked by you, will help you to overcome all difficulties, and in the course of time you will become used to this practice and will taste how sweet is the name of the Lord. Then you will learn by experience that this practice is not impossible and not difficult, but both possible and easy. This is why St. Paul, who knew better than we the great good which such prayer would bring, commanded us to pray without ceasing. He would not have imposed this obligation upon us if it were extremely difficult and impossible, for he knew beforehand that in such case, having no possibility of fulfilling it, we would inevitably prove to be disobedient and would transgress his commandment, thus incurring blame and condemnation. The Apostle could have had no such intention.
Moreover, bear in mind the method of prayer – how it is possible to pray without ceasing, namely by praying in the mind. And this we can always do if we so wish. For when we sit down to work with our hands, when we walk, when we eat, when we drink we can always pray mentally and practice this mental prayer – the true prayer pleasing to God. Let us work with the body and pray with the soul. Let our outer man perform his bodily tasks, and let the inner man be entirely dedicated to the service of God, never abandoning this spiritual practice of mental prayer, as Jesus, God and Man, commanded us, saying: "But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret"(Matthew 6:6).
The closet of the soul is the body; our doors are the five bodily senses. The soul enters its closet when the mind does not wander hither and thither, roaming among things and affairs of the world, but stays within, in our heart. Our senses become closed and remain closed when we do not let them be attached to external sensory things, and in this way our mind remains free from every worldly attachment, and by secret mental prayer unites with God its Father. "And thy Father which seeth in secret shall reward thee openly," adds the Lord. God who knows all secret things sees mental prayer and rewards it openly with great gifts. For that prayer is true and perfect which fills the soul with Divine grace and spiritual gifts. As chrism perfumes the jar the more strongly the tighter it is closed, so prayer, the more fast it is imprisoned in the heart, abounds the more in Divine grace.
Blessed are those who acquire the habit of this heavenly practice, 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. This mental prayer reaches to the very throne of God and is preserved in golden vials, sending forth their odors before the Lord, as John the Divine saw in the Revelation, "Four and twenty elders fell down before the Lamb, having every one of them harps, and golden vials full of odors, which are the prayers of the saints" (Revelation 5:8).
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.
So, brother, when you enter your closet and close your door, that is, when your mind is not darting hither and thither but enters within your heart, and your senses are confined and barred against things of this world, and when you pray thus always, you too are then like the holy angels, and your Father, Who sees your prayer in secret, which you bring Him in the hidden depths of your heart, will reward you openly by great spiritual gifts.
But what other and greater rewards can you wish from this when, as I said, you are mentally always before the face of God and are constantly conversing with Him – conversing with God, without Whom no man can ever be blessed either here or in another life?
Finally, my brother, whoever you may be, when you take up this book and, having read it, wish to test in practice the profit which mental prayer brings to the soul, I beg you, when you begin to pray thus, pray God with one invocation, "Lord have mercy," for the soul of him who has worked on compiling this book and of him who helped to give it to the public. For they have great need of your prayer to receive God’s mercy for their soul, as you for yours. May it be so! May it be so!
St Gregory Palamas, from "Early Fathers From the Philokalia," translated from the Russian text, "Dobrotolubiye," by E. Kadloubovsky and G.E.H. Palmer, eighth edition, (London: Faber and Faber, Ltd., 1981), pp. 412 - 415