Structure of The Book of Revelation

It is well recognized that most of the Book of Revelation is arranged around groups of sevens: seven churches, seven seals, seven trumpets, seven plagues, etc. The controversy stems around the chronology of these groups of seven. Does each set of events follow the previous one in chronological order, or does each set recap the same series of events but using different imagery? For a good defense of the latter view, see the classic study More Than Conquerers by William Hendricksen.  Since the printer's tray below contained two 7x7 grids, it seemed natural to use it to illustrate the Book of Revelation.

Sevens (2008) (22 1/2" x 17 1/2")

mixed media in printer's tray