7 These spirits, therefore, are lurking under the statues and consecrated images: these inspire the breasts of their prophets with their afflatus, animate the fibres of the entrails, direct the flights of birds, rule the lots, give efficiency to oracles, are always mixing up falsehood with truth, for they are both deceived and they deceive; they disturb their life, they disquiet their slumbers; their spirits creeping also into their bodies, secretly terrify their minds, distort their limbs, break their health, excite diseases to force them to worship of themselves, so that when glutted with the steam of the altars and the piles of cattle, they may unloose what they had bound, and so appear to have effected a cure.
The only remedy from them is when their own mischief ceases; nor have they any other desire than to call men away from God, and to turn them from the understanding of the true religion, to superstition with respect to themselves; and since they themselves are under punishment, (they wish) to seek for themselves companions in punishment whom they may by their misguidance make sharers in their crime. These, however, when adjured by us through the true God, at once yield and confess, and are constrained to go out from the bodies possessed.
You may see them at our voice, and by the operation of the hidden majesty, smitten with stripes, burnt with fire, stretched out with the increase of a growing punishment, howling, groaning, entreating, confessing whence they came and when depart, even in the hearing of those very persons who worship them, and either springing forth at once or vanishing gradually, even as the faith of the sufferer comes in aid, or the grace of the healer effects. Hence they urge the common people to detest our name, so that men begin to hate us before they know us, lest they should either imitate us if known, or not be able to condemn us.
Source: The Treatises of Cyprian (New Advent)