This if from the Screwtape letters by cs Lewis.
MY DEAR WORMWOOD, subject of prayer. You might have spared the comment that my advice about his prayers for his mother it "proved singularly unfortunate". The best thing, where it is possible, is to keep the patient from the serious intention of praying altogether. When the patient is an adult recently re-converted to the Enemy's party, like your man, this is best done by encouraging him to remember, or to think he remembers, the parrot-like nature of his prayers in childhood. In reaction against that, he may be persuaded to aim at something entirely spontaneous, inward, informal, and unregularised; and what this will actually mean to a beginner will be an effort to produce in himself a vaguely devotional mood in which real concentration of will and intelligence have no part. One of their poets, Coleridge, has recorded that he did not pray "with moving lips and bended knees" but merely "composed his spirit to love" and indulged "a sense of supplication". That is exactly the sort of prayer we want; and since it bears a superficial resemblance to the prayer of silence as practiced by those who are very far advanced in the Enemy's service, clever and lazy patients can be taken in by it for quite a long time.
At the very least, they can be persuaded that the bodily position makes no difference to their prayers; for they constantly forget, what you must always remember, that they are animals and that whatever their bodies do affects their souls. It is funny how mortals always picture us as putting things into their minds: in reality our best work is done by keeping things out. If this fails, you must fall back on a subtler misdirection of his intention.
Whenever they are attending to the Enemy Himself we are defeated,...But of course the Enemy will not meantime be idle. Wherever there is prayer, there is danger of His own immediate action. He is cynically indifferent to the dignity of His position, and ours, as pure spirits, and to human on their knees He pours out self-knowledge. if ever he consciously directs his prayers "Not to what I think thou art but to what thou knowest thyself to be", our situation is, for the moment, desperate. Once all his thoughts and images have been flung aside or, if retained, retained with a full recognition of their merely subjective nature, and the man trusts himself to the completely real, external, invisible Presence, there with him in the room and never knowable by him as he is known by it—why, then it is that the incalculable may occur.