“Prayer without ceasing is necessary for all Christians. 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.
As 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.”
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