My beloved brother in Christ I wish you be well! Today I received your letter and I am going to answer to all those you wrote me about. The things you asked me about don`t require time or toil to think about what to answer.
For me the mental prayer is like anyone else`s skill since I`ve been working on it for thirty six years and even more.
When I came into the Holy Mountain I sought first the hermits who practiced the prayer. In those times – forty years ago – there were many who had life in themselves. Virtuous people, old men from the yore. From these we chose us elders and advisers.
Thus the practise of the mental prayer is to force yourself to say the prayer without cease. At the beginning fast for not allowing the mind to bring in vain thoughts. Take heed only at the words: `Lord Jesus Christ have mercy on me.`
After doing this for a long time the mind will get used with it and will say it permanently. And you`ll delight yourself with it as if you had honey in your mouth and you`ll wish to say it all the time. If you leave it you get sad.
When the mind gets used with it and fills itself with it – learning it well – then it send it to the heart. Because the mind is the one which nourishes the soul and any good or bad thing it sees or hears its job is to take it down he heart where is the centre of the spiritual and physical power of the man, the throne of the mind. When the one who prays keeps his mind out of imagination and takes heed only at the words of the prayer, then breathing softly, with a certain restraint and endeavor takes it down to the heart and keeps it there as if in a grasp and utters the prayer rhythmically `Lord Jesus Christ have mercy on me!`
At the beginning he says the prayer a few times and breathes once. Afterwards when the mind gets used to stay in the heart says at each breath a prayer. `Lord Jesus Christ ` and inspires then ` have mercy on me`and expires. This is repeated until the Grace descends over him and begins to work within his soul. After this everything is contemplation.
The prater can be said everywhere sitting or lying in bed or walking and standing. `Pray without cease. Give thanks in everything`, says the Apostle. You don`t have to pray only when you go to sleep but also when you stand up or you sit down. Struggle is required. When you get tired sit down. Then stand up again for not falling asleep.
These are called `accomplishment`. You show your good intention to God. Then everything depends on Him, if He gives it to you. God is the beginning and the end. His Grace accomplishes everything. He is the motive force.
How love is born and works depends on the accomplishment of the commandments. When you wake up during night and pray when you see the sik and empathize with him, when you see the widow, the orphans, the old men and have mercy for them then God loves you. And you love Him. He loves first and pours His Grace. And we give Him the same from the same, `Yours from Yours`
If you seek to find Him only through Prayer  don`t breath without Prayer. But take care not to accept imaginings because God is shapeless, He can`t be comprised in images without color, He is beyond perfection. He can`t be subdued to reasonings. He works like a breeze in our minds.
Humbleness comes when you think about how much you saddened God when He is so kind, so merciful, so full of love, Who was crucified and suffered everything for us. When you think about all these and many others suffered by God they bring you humbleness.
Thus if you utter the prayer without cease in two or three months you will get used with it. Grace will adumbrate you and will cool you. Only say it aloud without cease. And when the mind takes it over then you`ll have rest and you won`t say it with your mouth. Then again when the mind leaves it the mouth takes it over. The tongue has to make the effort at the beginning until you get used with it. Afterwards in all the years of your life the mind will say it without effort.
When you come in the Holy Mountain as you say come and see us. But then we`ll talk about other things. You won`t have time left for prayer. You`ll find prayer when your mind is quiet. If you go to monasteries and other places your mind will be dispersed at those things you shall see and hear.
I am sure you will find the prayer. Do not doubt that! Only knock straight at the door of the divine mercy and Christ will open to you. It is impossible not to open for you. Love Him a lot in order to receive a lot. On your love for Him be it much or little it depends the devotedness, be it much or little.
 it refers at the prayer : Lord Jesus Christ have mercy on me or the Jesus prayer.
Excerpt from Testimonies of the monachal experience– Pious Joseph the Hesychast, Evanghelismos.