Prayer of the Heart
The prayer of the heart is the ancient monastic prayer of the Hesychast tradition “Lord Jesus Christ Son of God Have Mercy on me a sinner”. The scriptural roots of the Jesus Prayer lie in St Luke’s Gospel in the parable of the Publican and Pharisee, while the pharisee in prayer wallows in his self-rightousness, the publican in humility is aware of his unworthiness in the awesome presence of God, he prays “Lord be merciful to me a sinner (18:13)”.
St Paul exhorts us to “pray unceasingly” in his 1st letter to the Thessalonians (5:17). It is a prayer said with the lips, understood by the mind which then descends into the depths of our heart and transforms us. St John Chrysostom says
“The name of our Lord Jesus Christ, descending into the depths of the heart, will subdue the serpent holding sway over the pastures of the heart, and will save our soul and bring it to life. Thus, abide constantly with the name of our Lord Jesus Christ, so that the heart swallows the Lord and the Lord the heart, and the two become one. But this work is not done in one or two days; it needs many years and a long time. For great and prolonged labor is needed to cast out the foe so that Christ dwells in us.” St John Chrysostom (d. 407) in Writings from the Philokalia
Listen to the wise words of a living saint, Jean Vanier on what authentic prayer is.
More reference material may be found at this website. http://www.jesusprayer.us