Celsus appears to me to have misunderstood the statement of the apostle, which declares that “in the latter times some shall depart from the faith, giving heed to seducing spirits and doctrines of devils; speaking lies in hypocrisy, having their conscience seared with a hot iron; forbidding to marry, and commanding to abstain from meats, which God has created to be received with thanksgiving of them who believe;” and to have misunderstood also those who employed these declarations of the apostle against such as had corrupted the doctrines of Christianity.
And it is owing to this cause that Celsus has said that “certain among the Christians are called 'cauterized in the ears;'” and also that some are termed “enigmas,” — a term which we have never met. The expression “stumbling-block” is, indeed, of frequent occurrence in these writings—an appellation which we are accustomed to apply to those who turn away simple persons, and those who are easily deceived, from sound doctrine. But neither we, nor, I imagine, any other, whether Christian or heretic, know of any who are styled Sirens, who betray and deceive, and stop their ears, and change into swine those whom they delude.
And yet this man, who affects to know everything, uses such language as the following: “You may hear,” he says, “all those who differ so widely, and who assail each other in their disputes with the most shameless language, uttering the words, 'The world is crucified to me, and I unto the world.'” And this is the only phrase which, it appears, Celsus could remember out of Paul's writings; and yet why should we not also employ innumerable other quotations from the Scriptures, such as, “For though we do walk in the flesh, we do not war after the flesh; (for the weapons of our warfare are not carnal, but mighty through God to the pulling down of strongholds,) casting down imaginations, and every high thing that exalts itself against the knowledge of God?”
Source: Against Celsus (New Advent)