One of the oldest fragments of New Testament scripture we have is a piece of Revelation that identifies the number of the beast as 616, rather than 666. It is also interesting to note that the last verses of Revelation give a specific punishment for people who alter the book, almost as though John foresees people changing the words that he wrote.
>Revelation 22:18-19 For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book: And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book.
Is it possible that there are some parts of Revelation that reveal more specific events that happen at the end of the world? And likewise are some of the verses we read made up to obscure us from the truth? This may also account for why eschatologists still have very different interpretations of what the prophecy reveals.