One thing v. 1 teaches us is that since Revelation is a revelation from God to His Son who then gave it to His servants, we know that every word in it is true. But that doesn’t mean that we are to take every word literally. As we will shortly see, that is impossible. If we take some words literally, we will have to take other words figuratively. Or vice versa.
The book of Revelation can be intimidating. It is chock full of mysterious symbols: beasts, lampstands, Spirits, numbers, stars, seals, etc.
Yet we have to remember the book is a revelation from Christ to His servants. It is also a letter to His church, specifically the seven churches in Asia. Christ used this letter to communicate something to them, and subsequently to us. We should expect, then, for Revelation to be understandable. And thus we should expect to learn something from it.
Paul explains how this process of revelation to understanding works in Ephesians 3. He is telling the Gentile believers in Ephesus how they, who were once far off from God had been brought near by the blood of Christ. He then pauses to explain that while it was known to Old Testament faithful that God would bless the Gentiles, how that would exactly happen remained a mystery.
Paul goes on the explain “how the mystery was made known to me by revelation” (v. 1) and “revealed to His holy apostles and prophets by the Spirit” (v. 5). So now Paul can explain this mystery to believers in his day.
Christ’s revelation to John worked the same way.
In this case, the mystery was the coming of Christ the King in judgment against apostate Israel/Jerusalem. This judgment was a continuous theme of multiple prophets throughout the Old Testament, and was partially fulfilled with the defeat of both Israel and Judah. But Christ made it clear in His first coming that there was more judgment on the way:
O Jerusalem, Jerusalem, the city that kills the prophets and stones those who are sent to it!