Most of the “over 400 early Christian manuscripts” were written long AFTER John penned Revelation & declared the canon of Scripture closed (Revelation Ch.22).
Here you have made a common mistake. Revelation 22 did not close the canon of scripture, and why that is the case is important.
Revelation 22:18-19 – Adding to the Word of God
catholic.com/thisrock/1992/9211qq.asp
Q: Revelation 22:18-19 says, “I warn everyone who hears the prophetic words in this book; if anyone adds to them, God will add to him the plagues described in this book, and if anyone takes away from the words in this prophetic book, God will take away his share in the tree of life and in the holy city described in this book.” Doesn’t this verse render the Catholic doctrine of sacred Tradition scripturally unviable since your Tradition is added to the Bible?
A: That conclusion might be possible if John’s phrase “this book” meant “the Bible,” but it doesn’t. It’s a common mistake of Evangelicals and Fundamentalists to assume that John was speaking here of the Bible as we know it - all 73 books (seven less in Protestant versions), from Genesis to Revelation, bound between two covers.
John wrote Revelation before the year 100, so he could not have had the Bible in mind when he penned this warning, because the Bible as we know it (and as many Protestants think he meant it) would not exist in its present form for three centuries.
The Catholic Church defined the canons of the Old and New Testaments at the councils of Hippo (393) and Carthage (397). Before that time Christians weren’t certain exactly which books belonged in the canon because the Church hadn’t yet made a definitive decision on the issue.
Besides, oral Tradition isn’t something added to the Bible. Paul tells us in 2 Thessalonians 2:15 that Tradition comes to us in two forms, written and oral. He exhorts us to “stand firm and hold fast” to both the oral form and the written form of Tradition. In other words, the Lord gave the Church the Bible and oral Tradition as the two ways of preserving and handing on a single thing, the revealed Word of God.
There’s another reason Revelation 22:18-19 doesn’t disprove the Catholic doctrine of Tradition. **Virtually the same warning is given in Deuteronomy 4:2. **If we apply there the same principle that you want to apply in Revelation 22, we have a dilemma, because God would have prohibited the adding of anything to his statutes and decrees as found up to and including the book of Deuteronomy. If that were the case, all subsequent books of the Bible, including the book of Revelation itself, would be proscribed because they were added to the Pentateuch. That means Jeremiah and Ezekiel and Paul and John and all the writers of later books would have the aforementioned dreaded plagues “added unto them” because they added to what was already there.
So what was John really warning us about in Revelation 22? Simple. He had written the book of Revelation as a prophetic document for the edification and guidance of the Church, and he didn’t want it tampered with - nothing added, nothing subtracted. He knew that some knucklehead in a later generation might decide he could improve on the message, or, like the Jehovah’s Witnesses, twist it to better suit his personal theology. Revelation 22:1819 is essentially a first-century copyright, designed to discourage people from altering the work.
Unfortunately, the anonymous “emendation” of texts was rife in the early centuries of the Church, and bishops had to exercise extreme caution in verifying the authorship of the many “holy books” that were in circulation.
Even in Paul’s day there were con artists trying to pass off bogus “scripture” to unsuspecting Christians (many of whom only too readily took the bait): “We ask you, brothers. . . not to be shaken out of your minds suddenly or to be alarmed either by a ‘spirit’ or by an oral statement or by a letter allegedly from us to the effect that the Day of the Lord is already at hand. Let no one deceive you in any way” (2 Thess. 1:1-3).