The Jesus Prayer, "O Lord Jesus Christ, Son of God, have mercy on me, a sinner" is one of the most ancient prayers of the Christian Faith, being an amplification of the cry of the publican in the parable which Christ related to His disciples (Luke 18:13-14). In this our Saviour has provided his followers with an example of a penitential prayer which justifies the one who uses its words with sincerity.
Bishop Ignatius (Brainchaninov) was among the first spiritual writers to stress the Christian antiquity of the Jesus Prayer. His exposition on its proper use and effects is founded firmly on the teachings embodied in 'The Philokalia', the renowned compilation of the works of the ancient ascetic writers and later hesychast authors, the purpose of which is to lead its readers to 'theoria', the true contemplation of the Godhead in Its divine energies.
As he examines the teachings of the great fathers of the Church on the prayer of the heart, Bishop Ignatius, like most mature Orthodox spiritual writers, is careful to emphasise the dangers of falling into delusion by attempting to attain the vision of divine light through one's own efforts. The use of the Jesus Prayer under the instruction of an experienced spiritual guide is, according to him, preferable, Yet in these dark times, when guides experienced in the use of the Jesus Prayer are few and widely scattered throughout the world, we may gropingly by the direction of the writings of the holy Fathers to the treasury of spiritual knowledge and also…gropingly select for himself what is suited to his needs (p.84). -- Foreward
Author: Bishop Ignatius Branchianinov