Against Marcion 1.20

To this most straightforward proof we must add a defence against the clamour of the other side. For they say that Marcion did not so much innovate the rule by separating law and gospel as restore it after it had earlier been adulterated. O Christ, most patient Lord, who put up with the perversion of your preaching for so many years, until, of course, Marcion should come to your rescue! For they also bring up Peter himself and the others, the pillars of the apostleship, as having been rebuked by Paul for not walking with a straight foot toward the truth of the gospel — by that Paul, surely, who, still raw in grace and indeed anxious lest he had run or was running in vain, was then conferring for the first time with the apostles who came before him. If, then, still fervent as a neophyte against Judaism, he thought something in their conduct deserved rebuke — namely, their table-fellowship that shifted with the company — though afterwards he himself was in practice to become all things to all, that he might gain all, to the Jews as a Jew and to those under the law as under the law: do you want that rebuke, which concerned conduct alone, and conduct that would later please its own accuser, to be held suspect of a betrayal of the preaching about God as well? On the contrary, concerning the unity of the preaching, as we read above, they had joined right hands, and by the very division of their tasks had agreed on their partnership in the gospel; as he says elsewhere too: “Whether it was I or they, so we preach.”

And even if he wrote that certain false brothers had crept in who wanted to transfer the Galatians to another gospel, he himself shows that this adulteration of the gospel aimed not at transferring them to faith in another god and Christ but at keeping the discipline of the law: he catches them, that is, insisting on circumcision and observing times and days and months and years of Jewish ceremonies, which they ought to have recognized as already set aside according to the renewed arrangement of the Creator, who had long ago proclaimed this very thing through his prophets. So through Isaiah: “The old things have passed away,” he says; “behold, the new things which I now make.” So too through Jeremiah: “And I will make a covenant, not such as I made with your fathers when I brought them out of the land of Egypt”; and elsewhere: “Break up for yourselves new fallow ground, and be circumcised to your God, and circumcise the foreskins of your heart.” So the apostle, establishing this circumcision and this new ground, was dissuading them from those old ceremonies as well, which their own founder declared would one day cease, through Hosea: “And I will turn away all her mirth, and her feast days, and new moons, and sabbaths, and all her ceremonies.” So too through Isaiah: “Your new moons and sabbaths and the great day I cannot bear; your holidays and fasting and feast days my soul hates.” If, then, the Creator had long since rejected all these things and the apostle was declaring that they must now be rejected, the apostle's very judgment, in agreement with the Creator's decrees, proves that no other god was preached by the apostle than the one whose decrees he wished now to be acknowledged; and in this cause he brands as false both the apostles and the brothers who were transferring the gospel of the Creator's Christ from the newness foretold by the Creator to the oldness rejected by the Creator.