Luther did at one point attempt to remove the books of Hebrew, James, Jude, and Revelation. Why? The simple answer is that they didn't seem to him to fit into the overall theology that he held to. But it is fruitless to fight against Gods Word. It is eternal.
But it is wrong to claim that Luther actually removed the books from his canon. In fact, he completed his own translation of the Bible in 1522 and it contained the complete NT that we know today. Even after Luther finished his translation, he continually revised it. Phillip Schaff has pointed out, “He never ceased to amend his translation. Besides correcting errors, he improved the uncouth and confused orthography, fixed the inflections, purged the vocabulary of obscure and ignoble words, and made the whole more symmetrical and melodious. He prepared five original editions, or recensions, of his whole Bible, the last in 1545, a year before his death. This is the proper basis of all critical editions.”Great care and work went into Luther’s Bible. This means that every book in the Bible was given great concern and attention. No book of the Bible was left un-translated.
Luther wrote this statement in his original Preface To The New Testament in 1522:
“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.”
Hence, this is one of the most common arguments that has been used to discredit Luther. But a thorough study of Luther shows that he did not exercise authoritarian control over the canon. He was wrong in many of his teachings about some of what he taught, but he was striving to be a borean and test all things. (1Thess 5:21)