Luther is reported to have said that if a tyrant succeeded in destroying the Holy Scriptures and only a single copy of the Epistle to the Romans and of the Gospel of John escaped him, Christianity would be saved. He spoke truly; for the fourth Gospel presents the object of the Christian faith in its most perfect splendor, and the Epistle to the Romans describes the way of faith which leads to this object, with an incomparable clearness. What need of more to preserve Christ to the world and to give birth ever anew to-the, Church ? [Frederic Louis Godet, Commentary of John's Gospel, Kregel 1980 reprint of Funk and Wagnall's 1886 edition - p. 2].Frederic Louis Godet did not include this comment in early editions of the commentary (for instance, this comment is not found in the 1876 edition). The quote in its popular form can be found as early as 1881:
It is no wonder that in all ages this has been regarded as the most remarkable of our four Gospels. Testimony after testimony to this could be quoted from leading minds through the centuries. Luther's words are often quoted: "This is the unique, tender, genuine, chief Gospel. . . . Should a tyrant succeed in destroying the Holy Scriptures and only a single copy of the Epistle to the Romans and the Gospel according to John escape him, Christianity would be saved."Another variation from 1903-1904 states,
And Luther said, "This is the unique, tender, genuine, chief Gospel, far preferable to the other three. * * * Should a tyrant succeed in destroying the Holy Scriptures, and only a single copy of the Epistle to the Romans and the Gospel according to John escape him, Christianity would be saved."I could find no helpful documentation verifying "Should a tyrant..." etc. If it exists at all, it sounds like a Table Talk utterance. As shown above, sometimes the quote is linked with a genuine statement from Luther: "This is the unique, tender, genuine, chief Gospel, far preferable to the other three." This comment comes from Luther's Preface tot the New Testament (1522, omitted in later editions],
If I had to do without one or the other—either the works or the preaching of Christ—I would rather do without the works than without his preaching. For the works do not help me, but his words give life, as he himself says [John 6:63]. Now John writes very little about the works of Christ, but very much about his preaching, while the other evangelists write much about his works and little about his preaching. Therefore John’s Gospel is the one, fine, true, and chief gospel, and is far, far to be preferred over the other three and placed high above them. So, too, the epistles of St. Paul and St. Peter far surpass the other three gospels, Matthew, Mark, and Luke.
In a word St. John’s Gospel and his first epistle, St. Paul’s epistles, especially Romans, Galatians, and Ephesians, and St. Peter’s first epistle are the books that show you Christ and teach you all that is necessary and salvatory for you to know, even if you were never to see or hear any other book or doctrine. Therefore St. James’ epistle is really an epistle of straw, compared to these others, for it has nothing of the nature of the gospel about it. But more of this in the other prefaces. [LW 35:362].