The Seven Trumpets are governed by four intrinsic movements from earth to heaven and back. Why and what do these continual movements mean?
First, St. John witnesses the first four trumpets blown from heaven and their effect on the natural environment of wicked men. Next, the events move from heaven to Earth where we see a mighty angel proclaiming that there shall be no more delay and he sends his witnesses to witness against the city where the Lord has been crucified.
Next, we move back up to heaven and see the Woman clothed with the sun and the dragon. A cosmic battle ensues between the dragon and St. Michael the Archangel and once more the events are brought back down to Earth where the dragon is in hot pursuit after the offspring of the woman.
Finally, we move back up to heaven and see the Lord and the 144,000 accompanying him immediately before the close of the section of the Trumpets.
These movements help to explain how the Liturgy works: the entire process is liturgical and shows that the liturgy (heaven) is inherently involved in the history of the world and that in more ways than one the liturgy shapes the history of mankind.
We also are given to understand that the devil wants to disrupt the Liturgy more than anything else because he knows where the true power lies.