Tertullian — Against Marcion 1.20
To this most ready proof a defense from us is also needed against the other side’s outcries. For they say Marcion did not so much innovate a rule by separating law and gospel as restore one formerly adulterated. O Christ, most patient Lord, who for so many years endured the overturning of your preaching until Marcion came to help you!
For they also oppose Peter and the other pillars of apostleship as rebuked by Paul for not walking straight to the gospel’s truth—by that Paul who, still raw in grace and trembling lest he had run or be running in vain, was then first conferring with the apostles who preceded him. So if, still fervent as a neophyte against Judaism, he thought something in conduct reprehensible—that is, claiming common table—afterward he himself was about to become all things to all that he might gain all, to Jews as a Jew and to those under law as under law.
You want that rebuke of mere conduct—later to please its own accuser—to be suspected even of apostasy of preaching regarding God. Yet concerning unity of preaching, as we read above, they had joined right hands, and by the very distribution of office had agreed on fellowship of the gospel; and elsewhere: whether I or they, so we preach.
But even if he describes certain false brothers as having crept in who wanted to transfer the Galatians to another gospel, he himself shows that adulteration of the gospel aimed not at transferring faith to another God and Christ but at preserving the law’s discipline—catching them asserting circumcision and observing times and days and months and years of Jewish ceremonies they ought already to have recognized excluded, according to the Creator’s renewed disposition long preaching this through his prophets.
Through Isaiah: former things have passed; behold new things I now make; through Jeremiah: I will arrange a testament not such as I arranged with your fathers; renew a new renewal and be circumcised to your God in foreskin of heart. Establishing this circumcision and this renewal, the apostle also discouraged those ceremonial antiquities whose maker through Hosea and Isaiah professed festivals and sabbaths would cease. So if the Creator had long refused these and the apostle was already pronouncing them to be refused, the apostle’s own sentence agreeing with the Creator’s decrees proves no other god preached by the apostle than him whose decrees he wanted already recognized—branding false apostles and brothers who would transfer Christ’s Creator-gospel from the novelty the Creator foretold to the antiquity the Creator refused.
Latin
Huic expeditissimae probationi defensio quoque a nobis necessaria est aduersus obstrepitacula diuersae partis. aiunt enim Marcionem non tam innouasse regulam separatione legis et euangelii quam retro adulteratam recurasse. o Christe, patientissime domine, qui tot annis interuersionem praedicationis tuae sustinuisti, donec tibi scilicet Marcion subuenirct! nam et ipsum Petrum ceterosque, columnas apostolatus, a Paulo reprehensos opponunt, quod non recto pede incederent ad euangelii ueritatem, ab illo certe Paulo, qui adhuc in gratia rudis, trepidans denique, ne in uacuum currisset aut curreret, tunc primum cum antecessoribus apostolis conferebat. igitur si feruenter adhuc, ut neophytus, aduersus Iudaismum aliquid in conuersatione reprehendendum existimauit, passiuum scilicet (uindicans) conuictum, postmodum et ipse usu omnibus omnia futurus, ut omnes lucraretur, Iudaeis quasi Iudaeus et eis, qui sub lege, tamquam in lege, tu illam solius conuersationis, placiturae postea accusatori suo, reprehensionem suspectam uis haberi etiam de praedicationis erga deum praeuaricatione. atquin de praedicationis unitate. quod supra legimus, dexteras iunxerant, et ipsa officii distributione de euangelii societate condixerant. sicut et alibi: siue ego, inquit, siue illi, sic praedicamus. sed et si quosdam falsos fratres inrepsisse descripsit, qui uellent Galatas ad aliud euangelium transferre, ipse demonstrat adulterium illud euangelii non ad alterius dei et Christi fidem transferendam, sed ad disciplinam legis conseruandam habuisse intentionem, deprehendens scilicet illos circumcisionem uindicantes et obseruantes tempora et dies et menses et annos Iudaicarum caerimoniarum, quas iam exclusas agnouisse debuerant, secundum innouatam dispositionem creatoris olim de hoc ipso praedicantis per prophetas suos, ut per Esaiam: uetera transierunt. inquit, ecce noua, quae ego nunc facio. sic et per Hieremiam: et disponam testamentum, non quale disposui ad patres uestros, cum illos eduxissem de terra Aegypti; et alibi: renouate uobis nouamen nouum, et circumcidimini deo uestro, et circumcidimini praeputia cordis uestri. hanc ergo circumcisionem iam sistens apostolus et hoc nouamen, illas quoque uetustates caerimoniarum dissuadebat, de quibus idem conditor earum quandoque cessaturis profitebatur per Osee: et auertam omnes iocunditates eius et dies festos eius et neomenias et sabbata et omnes caerimonias eius. sic enim et per Esaiam: neomenias uestras et sabbata et diem magnum non sustineo, ferias et ieiunium et dies festos uestros odit anima mea. quodsi et creator omnia haec iam pridem recusauerat et apostolus ea iam recusanda pronuntiabat, ipsa sententia apostoli consentanea decretis creatoris probat non alium deum ab apostolo praedicatum quam cuius decreta cupiebat iam agnosci, falsos et apostolos et fratres notans in hac causa, qui euangelium Christi creatoris transferrent a nouitate praenuntiata a creatore ad uetustatem recusatam a creatore.\'