Revelation has one big goal: to let persecuted Christians know that God has their back and that one day soon he's going to strike down their oppressors. And he's going to do it big time.
Back around the end of the first century (source, p. 1187), when Revelation was written, there were scattered persecutions of Christians throughout the Roman Empire. Being a Christian was illegal, but depending on how mean the local authorities were, Christians could often fly under the radar.
Still, life was no picnic. Christians were in a constant struggle with the Roman way of life. Here's just a few things they couldn't (or shouldn't) be doing:
• Worshipping Roman gods (2:14, 20). Sure, all you had to do was light a stick of incense on an altar, but you'd be better off dead than committing idolatry.
• Following false prophets (16:13). Especially the ones who tell you it's okay to worship Roman gods (those are the same ones who preferred not to be executed).
• Using Roman money (13:14). After all, those coins say the Emperor is god. That's idolatry, too. Good luck buying bread.
• In fact, don't mix with The Beast (i.e., Rome) in any way (14:9-11). Wouldn't want to blend in too seamlessly with other Romans, now would we?
Obviously, this was a tall order for anyone who wanted to have any kind of a life in Rome. But presumably, Christians thought it was all worth it. After all, they were keeping themselves separate so that they could stay faithful and pure for the day when Jesus would return to carry them all up into Heaven (source, p. 1288). Fingers crossed, right?
But this was all taking a long time. People were being exiled. People were dying. Some of these Christians might have been wondering whether or not Jesus's watch was a little slow.
Enter John. It's the end of the 1st century and he's been exiled to Patmos for the crime of being Christian. So he wants to encourage other Christians out there to hold on for one more day—things are going to go their way very soon. These Christians need to keep the faith because Jesus really will be back very soon. John also wants them to know that Jesus has some awesome things planned for them (source, p. 1187). New robes, anyone?
Revelation also reassures these Christian churches that God is on their side and he's going to make their enemies pay. Big time. The martyrs probably speak for lots of persecuted Christians when they ask, "Sovereign Lord, holy and true, how long will it be before you judge and avenge our blood on the inhabitants of the Earth?" (6:10). To forgive is divine, but to laugh as your oppressors are ground up in the giant winepress of God's wrath is pretty great, too.
John writes all this to them in all kinds of cryptic symbols and secret codes to avoid detection. Clearly, the people reading his letter would have understood it. Otherwise, they would have just crumpled it up in a ball and thrown it away instead of passing it all around the Empire. He originally sends this to seven churches throughout Asia, but the letter manages to travel far and wide and eventually winds up in the Bible. It was kind of like required reading for the downtrodden.
Because it's such a product of its time and because it's so bizarre and cryptic, Revelation looks really weird to modern readers. The secret codes are really tough to crack unless you know oodles about the Hebrew Bible and ancient Roman history (source, p. 1188).
Believe us. Loads of people have tried to interpret Revelation without having a clue. That's why you'll sometimes hear about a politician or religious leader being the Beast. John was good, but even he didn't see visions of the current U.S. President rising out of the sea with seven heads.
Revelation is a series of visions. It's God's promise for his faithful. But, the irony is that, about two hundred and fifty years after John wrote Revelation, the Roman Emperor Constantine had a vision of his own.
During an especially brutal battle, he saw a vision of a cross in the sky. On it were written the words, "By this, you will conquer!" His troops wore the symbol and won the battle. Pretty soon Constantine had converted to Christianity. And suddenly, lots more people are converting and Christians are getting plum spots in Roman government (source).
Within less than one hundred years, Christians had taken over the Empire—soon to be the Holy Roman Empire. They hadn't forgotten their friends from the old days, though. Once Christianity became the official religion of the Empire, they destroyed Roman temples, outlawed holidays for their gods, and even persecuted non-Christians.
What can we say, Romans? They learned it from watching you.