Oceans. Seas. Lakes. Rivers. These waterways are all important for a growing society. Most of the Roman Empire was located on the sea, which made trade—and invasion—a whole lot easier. So it's no accident that the Book of Revelation frequently brings up bodies of water. Sometimes God's just destroying them and sometimes he's using them to enrich the life of the faithful. Go figure.
Taking down trade routes and access to fresh water is part of taking down Rome. Way to attack from the inside, God:
• Rivers turn to blood (8:9, 11:6, 16:4). It's probably God's favorite trick.
• Loads of fresh drinking water is poisoned when the star, Wormwood, falls to Earth (8:11).
• Fire gets thrown in the sea (8:8). Try sailing on that, Romans.
• Bodies of water are dried up (16:12).
Bad guys are also associated with bodies of water. The Sea Beast rises out of (what else) the sea (13:1), like our old pal, Rome, and the Whore of Babylon is sitting pretty on the water (17:5) (again, Rome). Merchants and sailors are also among some of the folks who weep for the destruction of Rome (18:19). Sure, just think of all the money they're losing now that they have to sail on seven seas of blood.
Probably the most ironic use of a body of water is in the Lake of Fire (19:20). Non-believers are sent there to soak for all eternity, but instead of relaxing in the cooling waters of a lovely lake, they'll be burning forever. Who wants some ice-cold refreshment now?
The good guys also get their moments with water, but they're portrayed much differently.
• In front of God's throne there's a sea of glass that looks like crystal (4:6).
• The Lamb guides the faithful to "the water of life" (7:17).
• Jesus's voice sounds like running water (19:6).
• God gives the thirsty water from the spring of life (21:6).
• A beautiful, crystal river flows through the New Jerusalem (22:1).
So this water is crystal-clear, sparkling, fresh and good for drinking (unlike all those bloody rivers down on Earth). Like the portrayal of water in the Gospels, Jesus also has water to offer the faithful. If they drink what he has, they'll never be thirsty again. If they take a sip from the same sea that gave us the Beast, they may not end up liking the taste of it.
You might have also noticed that bad guys are often mentioned in connection to lakes and seas. These are big, colossal bodies of water, kind of like the big, colossal Roman Empire. But they're also surprisingly stagnant. They kind of just sit there, unable to move or change. Sure, they're good for sailing huge cargo ships on, but they're also not going anywhere fast. They're stuck in one place.
But Heaven is filled with rivers and streams. These cool, crisp bodies of water are able to move and wind to their way to their destination. They're always active and varying. They can change course if they need be to navigate around rough spots. Sounds like the perfect symbol for God's (highly adaptable) people and the ways they navigated around the evils of Roman society.
Water is often portrayed as both dangerous and life-giving:
• In Jaws, the sea is a terrifying place where insane beasts (like sharks) might be lurking.
• The hero in Unbreakable might have super powers, but he almost drowns in a backyard swimming pool.
• In Open Water, two scuba divers are left behind to float for hours in the ocean. This makes the sharks very happy.
• The streams on Lost provide the crash-survivors lots of fresh, cool water to drink. They also have healing powers, so bonus.
• You'll sometimes see people cleaning up under the flow of a refreshing waterfall in movies or on TV. You'd think that baby would knock you right over, but nope. They make great showers.