“After this I looked, and behold, a door standing open in heaven! And the first voice, which I had heard speaking to me like a trumpet, said, ‘Come up here, and I will show you what must take place after this'” (Revelation 4:1 ESV).
As noted earlier, the second and third chapters of the Book of Revelation contain letters that were addressed to the seven churches referenced in Revelation 1:11…
“…’Write what you see in a book and send it to the seven churches, to Ephesus and to Smyrna and to Pergamum and to Thyatira and to Sardis and to Philadelphia and to Laodicea'” (ESV).
However, there is a subtle, yet significant, shift in our narrative as we transition from Revelation chapter three to Revelation chapter four. You see, the first verse of Revelation chapter four opens and closes with the words, “After this,” or, “After these things…” (NET). This leads to an important question: “After what things?” We can address that question by saying, “Here is what will follow these letters to the seven churches of chapters two and three.“
That brings us to Revelation 1:19 and the “Table of Contents” spoken of earlier: “Write the things which you have seen, and the things which are, and the things which will take place after this.” It’s interesting to note that the concluding words of Revelation 1:19 are the same words that open this 
passage from Revelation 4:1. Those words are “meta tauta” in the original language of each verse, or “after this.” In other words, the end of Revelation 1:19 corresponds with the beginning of Revelation 4:1.
With these things in mind, we can begin the process of tying these elements together. First, Revelation 1:19 provides us with a broad structural overview of this book:
- “Write… what you have seen…” This addressed everything our author witnessed up to that point.
- “What is now…” references the seven letters that Jesus dictated to the churches of Revelation chapters two and three.
- “And what will take place later” identifies what will happen in the future.
Thus, we have the past, present, and future encapsulated in one verse. Our place in this “Table of Contents” corresponds with the present “church age” referenced in Revelation chapters two and three. This is evidenced by the cautionary message that Jesus repeated to each of those churches: “Let those who can hear listen to what the Spirit is saying to the churches” (Revelation 3:22 TLB). Those messages would carry little or no significance if they were irrelevant to our present day.
So where does that leave us as we enter Revelation chapter four? The answer is the future, for Revelation chapter four embarks on a prophetic journey that will take us into a period that is yet to come.