To understand the book of Revelation, we need to understand that it is a book of prophecy, and the book of Revelation 1:3 identifies it as a book of prophecy. And as a book of prophecy, it has a number of similarities to Old Testament prophets. It mirrors, for example, some of what happens in Ezekiel. Some think that the sequence of the visions in Ezekiel had a very formative influence on the way that John had organized Revelation. We also see John having something like a prophetic commission, like what happens to Ezekiel. We see further that Ezekiel is called to write by the Spirit, and John is said to write at the leading of the Spirit, and that there's a divine authority that lies behind what he writes in Revelation. And so we see, just as the true prophets from the Old Testament are actually speaking the very words of God, we see the same thing in Revelation where, as John writes, he's writing the very words of God. Revelation is also much like the book of Daniel, which is also an apocalyptic prophecy type of book, which we find in Revelation. Revelation 1 begins with John saying, these are the things that must soon take place and these had been shown to him. And we find something very similar in Daniel 2, where the things that will happen in the latter days are going to be shown to them. So we see those similarities as well. Beyond this, the book of Isaiah is quoted a number of times in Revelation. And in fact, we could point to the way that John often takes Old Testament books, Old Testament wording, Old Testament images, and weaves them into his prophecy to demonstrate his continuity with the prophets that have come before. Some even say that John is writing the climax of biblical prophecy. If you look, for example, in Revelation 18 and 19 and the downfall of Babylon, it's been argued that he's actually taking all of the Old Testament statements about the downfall of Babylon from the prophets and weaving those into that account to demonstrate how his prophecy of the downfall of Babylon stands in continuity with what has come before.