Saint Paul exhorts us to "pray without ceasing" (1 Thess. 5:17). Most people pray, and some pray often, but how can we pray unceasingly? One of the best ways to accomplish this is through the Jesus Prayer. This prayer is very simple: "Lord Jesus Christ, Son of God, have mercy on me, a sinner." And yet it is very powerful: perhaps the best means of communion with God outside the Eucharist.
First of all, it is firmly rooted in Scripture. It is based on the prayer of the blind man: "Jesus, thou Son of David, have mercy on me," and that of the repentant Publican: "God, be merciful to me, a sinner." In addition, it invokes the Most-Holy Name of Jesus: "There is none other name under heaven given among men, whereby we must be saved" (Acts 4:12), and "Wherefore God also hath highly exalted Him, and given him a name which is above every name: that at the Name of Jesus every knee should bow, of things in heaven, and things on earth, and things under the earth" (Phil. 2:9,10). The apostle also tells, "No man can say, Lord Jesus, except by the Holy Ghost" (1 Cor. 12:3).
Furthermore, this prayer is awesome in its simplicity, consisting of only a dozen words. It is at once an affirmation of faith and repentance. When said in full diligence, humility and sincerity, avoiding vain repetition, the words and message of this beautiful prayer will engrain themselves in our being; as Saint Theophan the Recluse put it so beautifully, the Prayer becomes "a murmuring stream within our souls."
This book is an anthology by Igumen Chariton of Valamo, based on the notes he took out of the works of Sts. Theophan, Ignatii Branchianinov, the Sayings of the Desert Fathers, and of course, the Philokalia.