The Book of Revelation is such a confusing book. Why is it so difficult to understand?

The Book of Revelation was written as a time line, a sequence of prophetic events. It is a chronological "skeleton.” It is only the “bones” of the animal. The “meat” is not on the bones. The “flesh” is found in the Old Testament. The writer of Revelation assumed prior knowledge of the Old Testament revelation on the part of the reader. As a result, he simply indicated, through a phrase, where he expected the reader to go in the Old Testament for the full explanation. For example, Revelation 1:1 is a reference back to Daniel 2:28-29; Revelation 1:4 is filled out by consulting Isa. 11:2, and so on. When the reader follows this procedure and puts the “flesh” on the “bones,” then the Book of Revelation is quite simple to understand.