For all of our questions about Revelation, they are primarily contained in chapters 6-18. You can gain a good grasp of the book in the chapters preceding and following this section. Today’s reading is a challenging one. I would point out that the reading ends with a picture that I think is expressing two sides of God’s judgment. It is sweet for His children, but it is still bitter or sour for those who reject Him. Part of us should rejoice at His judgment and then we should grieve as well.
Terror and horror, I think, may describe the events that unfold in John’s description of the future for the unsaved, How can we stand by quietly and not share our faith with those we love who do not know Jesus?