"St. John Karpathisky in The Philokalia says that when in the prayer of Jesus we call upon the holy name and say, 'Have mercy on me, a sinner,' then to every such petition the voice of God answers in secret, ‘Son, thy sins be forgiven thee.’ And he goes on to say that when we say the prayer there is at that moment nothing to distinguish us from the saints, confessors, and martyrs."
Reference: French, R.M. The way of a pilgrim ; and, The pilgrim continues his way. Hope Pub House, 1991.