There are many ways in which Bible scholars approach the book of Revelation:-
(1) Most approach it with the view that it is not to be taken literally at all.
(2) The historical school regards the book as being largely fulfilled.
(3) Others regard the book as being incomprehensible and that it is impossible to arrive at any understanding of the mysteries that it contains.
(4) Finally, there are those who regard the book as literal, and that most of it is prophetic, awaiting fulfillment at some future date.
The approach to the interpretation of the book presented here is that it is literal, and most of it deals with future events.