Clementine Homilies

“But the reason why the demons delight in entering into men's bodies is this. Being spirits, and having desires after meats and drinks, and sexual pleasures, but not being able to partake of these by reason of their being spirits, and wanting organs fitted for their enjoyment, they enter into the bodies of men, in order that, getting organs to minister to them, they may obtain the things that they wish, whether it be meat, by means of men's teeth, or sexual pleasure, by means of men's members. Hence, in order to the putting of demons to flight, the most useful help is abstinence, and fasting, and suffering of affliction. For if they enter into men's bodies for the sake of sharing pleasures, it is manifest that they are put to flight by suffering. But inasmuch as some, being of a more malignant kind, remain by the body that is undergoing punishment, though they are punished with it, therefore it is needful to have recourse to God by prayers and petitions, refraining from every occasion of impurity, that the hand of God may touch him for his cure, as being pure and faithful.”