The Five Books Against Marcion by Tertullian
Chapter II.--St. Luke's Gospel, Selected by Marcion as His Authority, and Mutilated by Him. The Other Gospels Equally Authoritative. Marcion's Terms of Discussion, However, Accepted, and Grappled with on the Footing of St. Luke's Gospel Alone.
You have now our answer to the Antitheses compendiously indicated by us. I pass on to give a proof of the Gospel -- not, to be sure, of Jewry, but of Pontus -- having become meanwhile adulterated; and this shall indicate the order by which we proceed. We lay it down as our first position, that the evangelical Testament has apostles for its authors, to whom was assigned by the Lord Himself this office of publishing the gospel. Since, however, there are apostolic men also, they are yet not alone, but appear with apostles and after apostles; because the preaching of disciples might be open to the suspicion of an affectation of glory, if there did not accompany it the authority of the masters, which means that of Christ, for it was that which made the apostles their masters. Of the apostles, therefore, John and Matthew first instil faith into us; whilst of apostolic men, Luke and Mark renew it afterwards. These all start with the same principles of the faith, so far as relates to the one only God the Creator and His Christ, how that He was born of the Virgin, and came to fulfil the law and the prophets. Never mind if there does occur some variation in the order of their narratives, provided that there be agreement in the essential matter of the faith, in which there is disagreement with Marcion. Marcion, on the other hand, you must know, ascribes no author to his Gospel, as if it could not be allowed him to affix a title to that from which it was no crime (in his eyes) to subvert the very body. And here I might now make a stand, and contend that a work ought not to be recognised, which holds not its head erect, which exhibits no consistency, which gives no promise of credibility from the fulness of its title and the just profession of its author. But we prefer to join issue on every point; nor shall we leave unnoticed what may fairly be understood to be on our side. Now, of the authors whom we possess, Marcion seems to have singled out Luke for his mutilating process. Luke, however, was not an apostle, but only an apostolic man; not a master, but a disciple, and so inferior to a master -- at least as far subsequent to him as the apostle whom he followed (and that, no doubt, was Paul ) was subsequent to the others; so that, had Marcion even published his Gospel in the name of St. Paul himself, the single authority of the document, destitute of all support from preceding authorities, would not be a sufficient basis for our faith. There would be still wanted that Gospel which St. Paul found in existence, to which he yielded his belief, and with which he so earnestly wished his own to agree, that he actually on that account went up to Jerusalem to know and consult the apostles, |lest he should run, or had been running in vain;| in other words, that the faith which he had learned, and the gospel which he was preaching, might be in accordance with theirs. Then, at last, having conferred with the (primitive) authors, and having agreed with them touching the rule of faith, they joined their hands in fellowship, and divided their labours thenceforth in the office of preaching the gospel, so that they were to go to the Jews, and St. Paul to the Jews and the Gentiles. Inasmuch, therefore, as the enlightener of St. Luke himself desired the authority of his predecessors for both his own faith and preaching, how much more may not I require for Luke's Gospel that which was necessary for the Gospel of his master.