Since I was introduced to the Prayer by Fr Francis Horner SSM back in 1978, it has proved to be so for me. Not having been brought up a Christian, but in fact to distrust and avoid the church, it took me a long time to surrender to the insistence of the Holy Spirit. Fr Francis had the inspired - literally, I think - idea not so much to teach me the Jesus Prayer, but merely to give me a copy Per Olof Sjögren's little book on the Prayer, and to answer the questions I raised on reading it during the time I stayed at Willen Priory.
In the years since that summer at Willen I have rattled about the church a bit, finding it difficult to settle down, despite the trust that has too often been placed in me, but by God's grace the Prayer has kept hold of me, and I have practiced it more or less (often less) faithfully all that time. The Prayer is the way of a beggar indeed. It lays no claim to anything, but merely asks for mercy, as did the tax collector at the Temple in Jerusalem (Luke 18:9-14). Nothing more. Unlike the Pharisee, who runs through his spiritual resumé as he stands before the Lord, the tax collector won't even raise his eyes to heaven, but simply prays, "God, be merciful to me, a sinner!" By the time the Jesus Prayer had become a regular form of prayer in the Egyptian desert in the early Christian centuries, it had become, "Lord Jesus Christ, Son of God, have mercy on me, a sinner."
Irma Zaleski continues:
To call upon the name of Jesus so often, so insistently, is to knock again and again at the door of our own hearts: "the room within." This is the deepest centre of our being, where Christ lives, an essential fact of our faith that we often forget. In praying this prayer, we remember that Christ has always been there and will never leave us, no matter what we have done, no matter how greatly we have sinned. The Jesus Prayer is, for those who embrace it, a true, healing expression of our relationship with Christ."That of God" within us each, the indwelling Christ, reminds me of the way that the sun strikes a blade of grass very early in the morning, and each dew-drop sparkles with the purest light. That light is really sunlight, no matter how tiny the dew-drop; small as it is, fragile, imperfect and soon to evaporate, yet it holds for a moment the true light, to return it, as best it can, faithfully to the watching eye.