A little introduction, then the puzzle.
So we have John's introduction, then what I take to be the theme of the Revelation in Rev 1.7, "Behold, he is coming with the clouds, and every eye will see Him, even those who pierced Him; and all the tribes of the earth will mourn over Him. So it is to be."
The "coming of the clouds" takes from Dan 7.13, and so would be a reference to the ascension -- Jesus coming to heaven in the clouds (cf., Act 1.9).
This is all the more clear because we then see what Jesus is doing in heaven. The first picture, in Rev 1.9-20, is a picture of Jesus as priest in the heavenly holy place -- the room just outside of the Most Holy Place. We know this because this is where the lamps were in the OT temple/tabernacle. We know that the lamp stands are the churches (Rev 1.20). (Sorry, but no OT references right now -- not enough time to look them up.)
Rev 2-3, then, is the priest doing his work of taking care of the lamps -- trimming the wicks, adding oil, thinking about removing any defective lamp which no longer gives light.
We then move into the Most Holy Place in Rev 4. We know this because the ark is God's throne (2 Sam 6.2, 2 Kngs 19.15, 1 Chr 13.6, Ps 80.1, 99.1, Is 37.16). We also know this because of the sea in front of the throne (the violet veil in the tabernacle, and perhaps also the laver of water), and the door that John sees (the passage from the Holy Place to the Most Holy Place).
Now here's the puzzle: Why are the churches only in the Holy Place, and not in the Most Holy Place? This is, I think, related to a second puzzle: What's all this about writing a letter to the "angels" of the respective churches? After all, Jesus wants the letter sent to the seven churches (Rev 1.11), but sends those letter via the mediation of an angel (Rev 2.1 & etc.). (Yes, I recognize that "angel" only means "messenger," so the letter could be understood as sent to the churches' pastors. That's probably the interpretation I'm naturally most attracted to, but I just don't see it in the context of the Revelation. I "think" they're spiritual beings.)
After all, angelic mediation is a sign of OT administration (Acts 7.38, 53, Gal 3.19, Heb 2.2 -- this the also motivates the extended discussion in Heb 1 comparing Jesus with the angels in the context of the movement from the OT to the NT, and motivates Paul's passing references to revelations from angels in Gal 1.8 which, again, is supremely concerned with comparing Old and New Covenants).
Think also of the angels "mediating" between God and humanity at the Gate of the Garden of Eden (after the fall), in the veil separating the Holy Place from the Most Holy Place, and the angelic mediation on the ark as well.
But this just heightens the puzzle of why, then, Jesus communicates with the churches via the mediation of angels, just as he (Yahweh) communicated with Israel in the OT.
Here's a speculation. The Revelation is the story of the final transition from the Old Testament to the New Testament, i.e., is the working out of the immediate effects of Jesus' ascension. During this transitional period, there is overlap between Old Testament and New Testament practices. For example, Paul appears to takes a Nazarite vow (Acts 18.18) and undergoes ritual purification at the temple (Acts 21.23-24, 26, 24.18).
But the end of the transition places humanity in the position of dwelling immediately with God, without the mediation of angels.
This is suggested immediately by the well now account of the veil tearing when Jesus, the first fruit from the dead, dies on the cross. This also, I think, is the upshot of the theme in the book of Hebrews about Jesus "passing through the heavens" (Heb 4.14, 16, 6.20, 9.24). (This, also, is the issue regarding the waters divided and placed "above" the earth in Gn 1 -- this, visually, is the blue sky above. More critically, it is the "water barrier" that separates the highest heavens above from what is below, and is the floor of God's throne room, a la Ezekiel, Rev & etc.)
More poignantly, this is fully realized at the second coming, which fully reconciles heaven and earth ("there is no longer any sea" Rev 21.1) so that humanity now dwells in God's immediately presence -- i.e., angels no longer mediate God's presence to humanity (Rev 21-22).
And, thus also, at the end of the book, the angel tells John that he is only his fellow servant (Rev 19.10, 22.9).
So, in fact, during this transitional time, angels yet mediate between God and humanity in Rev 1-3. The remainder of the book then details the working out of Christ's ascension, in the definitive end of the Old Testament era. This taking away, then, places humanity in a direct relationship with God, in the sense of a relationship liturgically unmediated by angelic mediators. In effect, the church is more redeemed at the end of the book than at the first of the book, in the sense that the trappings of the OT era are definitively removed in the working out of the implications of Christ's ascension. The removal of the temple in the destruction of Jerusalem is the indication of this working out.
And this, then, is the reason that Luke identifies the destruction of the temple with the "drawing near" of the Christian's redemption (Lk 21.28). That is, after 70 A.D., the churches now, as it were, in the Holiest of Holies. (Actually, that would be an anachronistic way of putting it. The separation between the Holy Place and the Most Holy Place have been removed; that's why the churches are now in God's throne room, Eph 2.6, Col 3.1, Heb 12.20-28.)
Now, please, I know that there's just a ton of speculation there. Additionally, there's the remaining question of whether the argument now presents an over realized eschatology. I, obviously, want to preserve the now-but-not-yet aspect of Christ's revelation. Jesus has yet to return visibly, and the new heavens and new earth are not manifest.
But the angelic mediation in Rev 2-3 would seem to present a real challenge to the inaugurated eschatology of the Epistles that we have up to that point. Unless the angels ("messengers") are pastors, or unless the situation in Rev 2-3 changes in the remainder of the book, then we have angelic mediation continuing into the New Covenant proper. That would seem to violate a central distinction between the way that God relates to humanity in the Old Testament and the New.
Anyway, I've been musing about that recently.