Already explained. By God's will, now only Protestants have both a correct OT Canon and NT Canon. That's the way how Protestants are authenticated.
Well, right off the bat, this makes no sense because Lutherans have an open canon, as
@MarkRohfrietsch can attest, and Anglicans and Episcopalians, and other Protestant denominations, have basically the same books in their Bibles as the Roman Catholics. The Authorized Version of the King James Bible includes the full 73 book canon, differing from the English translation of the Vulgate only in that the Psalter in the Challoner Douai Rheims is translated from the Septuagint, which I prefer as it has clearer Christological references. Unfortunately, due to a conspiracy between printers looking to save costs, and Non-Conformists and the Church of Scotland which rejected these books, since the late 18th century complete unabridged editions of the King James Bible have become quite hard to find.
Are you saying that only Catholics are legitimate?
If by Catholics, you mean Roman Catholics, then obviously not, since the Statement of Faith of Christian Forums admits any Christians who agree with the Nicene Creed and the apostolate of St. Paul and reject or agree not to discuss certain heresies like Gnosticism and KJVO. However the Nicene Creed requires us to confess a belief in One Holy Catholic and Apostolic Church, which Roman Catholics obviously interpret as meaning their church, whereas others interpret Catholicity on the basis of Apostolic Succession, such as the Anglicans and Old Catholics, and still others such as Lutherans interpret it on the basis of the qualities of the church, so Catholicity becomes synonymous with Lutheran Orthodoxy, which is why many Lutherans identify as Evangelical Catholics, while the Eastern Orthodox interpret Catholicity based on a combination of Orthodox belief and apostolic succession from Orthodox bishops, plus being in communion with the other legitimate Eastern Orthodox; the Eastern Orthodox also believe they are the true Roman Catholic church, since New Rome (Constantinople) was the seat of the Roman government, the persecuted Eastern Orthodox Christians of the former Ottoman Empire have always identified as Romans (Rumi in Arabic), and they are also Catholic for the reasons expressed above.
Some people substitute the word Universal for Catholic in the Creed, which is fine; the literal translation of the Greek word Catholic is “According to the Whole.” The other two ecclesiologies that are common are the Local Church ecclesiology, favored by Baptists and most Congregationalists, and many other evangelical churches with a congregational polity, in which each Local Church is the Church in its fullness, and the Invisible Church ecclesiology in which the Universal Church invisibly unites all Christians.
Of the churches I mentioned, I like a great many of them, and am an Eastern and Oriental Orthodox-leaning Congregationalist with strong Wesleyan influences, which makes me a Protestant at present.
However, the important takeaway is that Protestantism is not a unified entity, in that you have Waldensians, Moravians, Lutherans, Calvinists, Anglicans and Methodists, and then the Radical Reformation churches such as the Anabaptists and Mennonites, the Non-Conformists such as the Congregationalists, Baptists, etc, and Restorationists such as Quakers, the Christian Church/Disciples of Christ, the Adventists and others, and more recently the Pentecostals.
Additionally, not being a Protestant does not automatically make one a Roman Catholic. One could be Eastern Orthodox, Oriental Orthodox, Assyrian, Old Catholic, Russian Old Orthodox, Western Rite Orthodox, or Messianic Jewish. And these churches all use different canons, just as the Anglicans, Lutherans and early Calvinists use, or used, different canons. Indeed each of the four branches of Oriental Orthodox (Syriac/Indian, Coptic, Ethiopian/Eritrean and Armenian) has a different canon, and the Slavonic Eastern Orthodox churches use a different canon from the Greek and Eastern Mediterranean churches.
Or are you saying that the Jewish Canon is not legitimate?
There are at least two Jewish canons presently in use, that of the Rabinnical and Karaite Jews, and that of the Beta Israel, but neither is legitimate since they both lack the Gospels and other books of the New Testament. The same is also true of the Samaritan Canon.
Rather the controversy is always on whether the Apocrypha is legitimate!!!
On the contrary, very few people other than a handful of anti-Roman Catholic polemicists care about this, and this has not been the subject of serious debate for some time. Indeed with the deprecation of the 39 Articles of Religion in the Anglican churches of North America, the Apocrypha in the Episcopal Church and many of its more conservative successors are effectively protocanonical. For example, one of the two scripture lessons appointed for the feast of St. Luke the Evangelist in the Episcopal Church is the beautiful pericope “Honor a Physician” from Sirach.
Rather, of much greater controversy in antiquity, in the Reformation and even at present includes certain books in the New Testament. The canonical status of Revelation has always been controversial, and Martin Luther wanted to exclude it, along with the Epistles of Jude, James and Hebrews, from his German translation of the New Testament, however, because this was so controversial, he instead placed them at the end, and they are known as Luther’s Antilegomenna. Likewise, the Longer Ending of Mark, owing to its absence from the manuscripts of the Alexandrian text type, is currently the subject of controversy.
The Jews have the canonization all the times from King Hezekiah till Ezra till the Pharisees. Like I said, it is their testimony, it is their canonization. The only conflict lies in the apocryphal books.
The problem with that statement is that the Dead Sea Scrolls have validated both the Septuagint and the Ethiopian books, and the New Testament actually quotes from both. For example, Jude quotes from 1 Enoch.
Now, those Jewish manuscripts we have which predate the Crucifixion obviously have authority, because Second Temple Judaism was the Church, until the ministry of our Lord, at which time its authority transferred to Christianity, a process which began with the Crucifixion, and ended with the destruction of the Temple, at which time the Pharisees took over and a new form of Judaism, Rabinnical Judaism, emerged. The Beta Israel however do preserve something close to Second Temple Judaism, however, in their case, whatever authority they had, along with their collection of priceless relics such as the Ark of the Covenant, passed to the Ethiopian Tewahedo Orthodox Church after the conversion of Ethiopia in the fourth century.
Thus, your argument is objectionable to me because it rejects, purely on the basis of anti-Catholicism, several of the most beautiful books of Scripture, some of which were historically more important than books in the New Testament, despite the fact that the world’s largest Protestant denomination, the Anglican Communion, uses them, and has used them since its inception. Furthermore, in the process of delegitimizing yhe Catholic Church and these books, you have also delegitimized several churches you are apparently unfamiliar with, such as the Assyrian Church of the East, which dates from the fifth century and are doctrinally not very different from some Protestant churches, and the Syriac, Indian and Antiochian Orthodox churches, which like the Assyrian church has people who still speak Aramaic in the vernacular, Aramaic being the language actually spoken by Christ in the vernacular. All three of these churches are largely comprised of Jews who accepted Christ, and Jewish last names are very common in them. Indeed in the Indian Orthodox Church, there is an endogamous group descended solely from Jews who had converted to Christianity who survived a shipwreck while sailing to Kerala, home to Jews since around 200 BC, and the city where St. Thomas was martyred (and home to a large Jewish population until the 20th century, known as Kochin Jews, such as Vidal Sassoon, and a great many Christians, descended from converted Kochin Jews and Hindus).
Thus, I am deeply troubled that you attribute authority over the Christian Bible to the leadership of a religion comprised of those Jews who did not accept Christ, while denying the legitimacy of those churches that have the most descendants of Jews who did accept Christ in antiquity, as well as Messianic Jews who consist at least in part of Jews who have recently accepted Christ.