In many ways the next three chapters form the theological centerpiece of the book of Revelation. In just the same way that they appear roughly in the middle of the book, they explain the reason for the visions that have come before and will come after.
Chapters 12 through 14 introduce us to the great antagonists of the church. These chapters are so important because they give us the reason for all the persecution and trial the church is going to experience in the last days. Why is all of this happening? Who is behind the devastating events coming upon the earth? What is the nature of the battle we find ourselves in?
Those are important questions. As most of us read Revelation we are most interested in the "when" questions. We love to piece together the sequence and the timing of all the things revealed in John's visions. But I would submit to you that this is not John's primary interest at all - especially in these central chapters. These chapters contain visions that take us in both directions time-wise. They stretch back to the creation of the world. They take us back to the birth of Christ. And they take us into the future events coming upon this earth - sometimes all in one vision, with little or no explanation. In other words, these central visions deal more with the meaning of events around us than the timing of these events.