1 Timothy 4:1

As those who adhere to the faith are fixed on a safe anchor, so those who fall from the faith can nowhere rest; but after many wanderings to and fro, they are borne at last into the very gulf of perdition. And this he had shown before, saying, that some had "already made shipwreck concerning the faith," and now he says, "Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits." This is said of the Manichaeans, the Encratites, and the Marcionites, and the whole of their tribe, that they should hereafter depart from the faith. Seest thou that this departure from the faith is the cause of all the evils that follow! But what is "expressly"? Plainly, clearly, and beyond doubt. Marvel not, he says, if some having departed from the faith still adhere to Judaism. There will be a time, when even those who have partaken of the faith will fall into a worse error, not only with respect to meats, but to marriages, and other such things, introducing the most pernicious notions. This refers not to the Jews, (for "the latter times," and a "departure from the faith," is not applicable to them;) but to the Manichees, and the founders of these sects. And he calls them very justly, "seducing spirits," since it was by these they were actuated in speaking such things.