"It seems to me necessary, at the outset of a discourse concerning the true worship of God, first of all to instruct those who have not as yet acquired any knowledge of the subject, that throughout the divine providence must be maintained to be without blame, by which the world is ruled and governed. Moreover, the reason of the present undertaking, and the occasion offered by those whom the power of God has healed, suggest this subject for a beginning, viz. to show that for good reason very many persons are possessed of demons, that so the justice of God may appear. For ignorance will be found to be the mother of almost all evils. But now let us come to the reason.