First of all, this is not a thread about religion. It is about the most popular method of prayer used by the Christian mystics and ascetics. It is at the very core of their practice and is considered by them to be the most powerful Christian prayer.
Also called The Prayer of the Heart, because it makes the mind descend into the heart, according to the mystics that practice it.
The Prayer in English is: Lord Jesus Christ, Son of God, have mercy on me, a sinner.
It is much like an eastern mantra. Repetition of this prayer invokes Jesus. Its final purpose is Theosis, or union with him.
The way this is to be prayed is continually. This method is from Thessalonians 5:17.
In the Greek tradition of mount Athos, this prayer annoys the devil, which will cause him to attack the one who prays it. I can personally confirm this. At that point, he who prays has two choices: to stop annoying the devil or to continue invoking Iesous, which will culminate in the defeat of the devil. But it's not that easy. He attacks in waves. Today he attacks, tomorrow he rests. Only real devotion will "activate" this prayer and ultimately defeat him.
The attacks are weird though. He is only as powerful as one lets him to be. For example, if a person is very attached to the world and to material wealth, the devil will seem very powerful to him. On the other hand, if he is detached from such things, the devil will be pretty weak, and so will his attacks. Quite an interesting dynamic. I also found that after each victory, he is banished, bit by bit, from the heart of the person.
Just thought I'd share it, for those interested in Christian mystical practices.
Also, here's a video of a traditional Greek Orthodox chant, explaining more about the prayer:
I'd be quite interested to discuss results, if anyone wants to give it a try.