The book of revelation was wrote before 70ad. It was written in an alagorical manner so the first century converts would understand the language and the roman government wouldn't therefore preserving it. Christ prophesized that Jerusalem would be destroyed, which it was by 70ad. The book of revelation was a warning to get out of Jerusalem before it fell. It was written to the seven churches, which are for the things must shortly come to pass. For the time is at hand. Not 2000 years later folks, back THEN.