There was a presbyter from Kellis...

…who was discerning. While coming into the church to complete the synaxis, he saw a number of demons outside the cell of one of the brothers. Some had taken the form of women who were speaking indecently, and others of blasphemous youths; others were dancing while still others were trying on different outfits. The old man sighed and said, “The brother persists in negligence in every way, and because of it the wicked spirits surround his cell in this disorderly manner.” Therefore, when he had completed the synaxis, he returned and entered the cell of the brother, and said to him, “I am suffering, brother. I have faith in you, and if you pray for me, God will completely relieve my heart from suffering.” The disciple was shamed, and said, “Father, I am not worthy to pray for you.” The old man persisted, pleading and saying, “I will not leave unless you promise me that you will say one prayer for me every night.” The brother obeyed the old man’s command. The old man did this because he wanted a new way to ensure that the brother would pray at night.

Therefore, when the brother rose in the night, he said the prayer for the old man. After finishing the prayer, he was struck with contrition, and said to himself, “Wretched soul, you pray for the old man, but you do not pray for yourself.” Therefore he offered one prayer for himself. He did this for a week, offering two prayers each night, one for the old man and one for himself.

On Sunday, while the old man was going to the church, he saw the demons once again standing outside the brother’s cell, looking glum, and the old man knew that the demons were grieved because the brother prayed. He was filled with joy and went to the brother, saying, “Have charity and offer another prayer for me each night.” After saying the two prayers for the old man, he was struck again with contrition, and said to himself. “O miserable one, offer another prayer for yourself.” He did this for a whole week, offering four prayers each night.
When the old man came again, he saw the demons glum and silent, and gave thanks to God, and went in again to the brother and urged him to offer another prayer for him. The brother also offered one for himself, and said six prayers at night. When the old man came again to the brother, the demons were angry with the old man, furious about the salvation of the brother. The old man gave glory to God and after entering his cell and exhorting him not to be negligent but the pray unceasingly, let him alone. The demons, seeing the brother’s perseverance in the prayers and in soberness, by the grace of God left him.