Miscellanies 2.20.117

So he says that sinners carry out the energies corresponding to the demons, but he does not say that the spirits themselves dwell in the unbeliever's soul. That is why he adds: “Take heed, that the temple of the Lord may be built gloriously. How? Learn: having received the forgiveness of sins and having hoped on the Name, let us become new, created again from the beginning.” For it is not the demons that are driven out from us, he says, but the sins are forgiven, which we committed like them before we believed. Fittingly, then, he set against this what follows: “Therefore in our dwelling place God truly dwells in us. How? His word of faith, his calling of promise, the wisdom of the ordinances, the commandments of the teaching.” I know of meeting a certain heresy, and its leader said that he fought pleasure with pleasure by using it, this noble knower deserting to pleasure through a feigned battle (for he claimed to be one who knows, too); since, he said, it is no great thing to abstain from pleasure without having tried it, but, when one is in it, not to be mastered by it; and therefore one should train oneself through it and in it.