According to whom?
Revelation is a very well understood Book in the Church.
Entire books are written about it. Commentaries on each passage are written on it.
Where in the world are you getting this stuff from? Making it up as you go?
Try Dr. Scott Hahn and his nearly 200 page book “The Lambs Supper: the Mass as Heaven on Earth”, he goes in depth into the book of Revelation in it.
To claim the book of Revelation is a “mystery” to the Church after 2,000 years is to be ignorant of 2,000 years of Christian study of the book of Revelation.
Maybe it’s a mystery to you; it is not a mystery to the Church who wrote the book, canonized the book, transmitted the book, spent thousands of hours meditating on the book, and wrote thousands of pages about the book.