Each stage has its own grace and an interplay and interdependance one with and upon the other.
* Firstly. The reciting of the Jesus Prayer out loud. We repeat the Jesus Prayer with our lips while trying at the same time to focus our attention on the words of the prayer.
* Secondly. Then the nous takes the Jesus Prayer and says it noetically . Our whole attention is found again in the words but it is concentrated on the nous [the soul's attention, the Eye of the soul]. When the nous gets tired then we start again to vocalize the prayer with the lips. After the nous has been rested we start again to concentrate our attention there.St. Neilos advises: Always remember God and your nous will become heaven.
* Thirdly. The Jesus Prayer then comes down into the heart. Nous and heart are now united and combined with each other. Attention is centered in the heart and it is immersed again into the words of the Jesus Prayer which has an invisible depth.
* Fourthly. The Prayer becomes now self-activating . It is done while the ascetic is working or eating or discussing or while he is in church or even while he is sleeping. “I sleep but by heart waketh” is said in the Holy Scriptures (Song of Songs 5:2).
* Fifthly. Then one feels a divine soft flame within his soul burning it and making it joyful . The grace of Christ lives in the heart. The Holy Trinity is established. “We become the habitation of God, when He lives within us, established in the memory. Thus we become the temple of God when Remembrance of His is not disturbed by earthly cares, and mind is not distracted by unexpected thoughts. Fleeing all that, the Friend of God withdraws into Him, chasing away the passions which invite intemperate thoughts, and occupying himself in a way which leads to virtue.” (Saint Basil the Great) Thus he feels the Divine Presence within himself and this grace passes through the body which becomes dead to the world and is crucified . And this is the extremist stage which is sometimes connected with the Vision of the Uncreated Light of the Holy Trinity.
Archimandrite Hierotheos Vlachos
“A Night in the Desert of the Holy Mountain”
Birth of Theotokos Monastery, Levadia, ISBN: 960-7070-04-6