The Apostle John wrote what he was inspired by direct revelation of the Holy Spirit to write concerning what the book of Revelation was. No more and no less. It was a prophecy, not a fifth gospel as Michael Rood states--again changing the Word of God.
Revelation 1:1 The Revelation of Jesus Christ, which God gave unto him, to shew unto his servants things which must shortly come to pass; and he sent and signified it by his angel unto his servant John: 2 Who bare record of the word of God, and of the testimony of Jesus Christ, and of all things that he saw. 3 Blessed is he that readeth, and they that hear the words of this prophecy, and keep those things which are written therein: for the time is at hand. ...http://www.seekgod.ca/roodteachings.htm#3
It is a puzzling thing. The truth knocks on the door and you say, "Go away, I'm looking for the truth," and so it goes away. Puzzling. Stop by the ETERNITY board for a contrarian approach to all mattersof life