The first section of Revelation chapter one, where we are introduced to the major players in the book and are told why it has been written. In the second section (chapters 2-3), the Lord addresses Revelation’s recipients directly and lists his concerns about their behavior. For most of them, there needs to be change.
In the third section, chapters 4 – 11, The Lord tells why there should be change, and the main reason is that His is going to hold the inhabitants of the earth accountable for their sins – including His own people.
Chapters 12-16, section four, say much the same thing, but with the addition of some details left out of 4 – 11. This section even begins much the same way as the last. Both open with a look into heaven. Both open with conflict – in chapter 5 the conflict is between earthly forces bent on conquest that hurt the lives of Christians. In chapter 12, the conflict is in heaven between forces of evil and the army of God. What is revealed to us is that the struggles of God’s people on earth are caused by a conflict that began in heaven. Because the forces of evil were defeated in heaven, we can be confident they will be defeated on the earth.