We saw in chapter 15 that God's people sang the song of God’s servant Moses and of the Lamb, they were worshipping. We were introduced to the seven bowls of God's wrath, which in chapter 16 we explore in more detail.
The judgements are reminiscent of both the seals and more specifically the trumpets, which in turn point back to the plagues found in the book of Exodus against Egypt. These plagues being poured out over the unrelenting world. This suggests that those found here are another view of the same judgements we've previously read, just experienced through another vision.
By drawing on Exodus we are again reminded that God protected His people through those plagues and God will do it again through these. Coming from the previous scene we see that the judgement comes following the worship of God's people. This points to the vindication of God's people who have been persecuted and suffered.
What has been added through the vision of the bowls compared to the trumpets is prasie. Recognising that God is holy and is full of justice. John heard the angel in charge of the waters say:
“You are just in these judgments, O Holy One, you who are and who were; for they have shed the blood of your holy people and your prophets, and you have given them blood to drink as they deserve.” (Revelation 16:5-6)
This emphasizes the justness of God's punishment of the wicked. In Exodus, we see the Nile turned to blood to avenge the killing of the infant Hebrews by Egypt. We also see here darkness causing pain. Yet the world still doesn't; repent.
The Euphrates is a large river that has never dried up. The prophecy here is that this great river will dry up due to the sin in the world. See Isaiah 50:2 where it is Israel's sin that causes God's judgement which turns rivers into deserts. The river acted as a natural boundary between two great empires, the Romans and the Parthians, (famous for the archers on horseback). Without a river, the empire would be able to strike from the east. This threat shows that it wouldn't be nature's doing, but rather God's planned action.
We see frogs, unclean, ugly, and often vicious creatures coming out of other beings adding to the vibrant and colourful imagery used to show the state of the world. Armageddon being a place found in Judges 5:19 and 2 Kings 23:29 is a scene of previous battles. Likely to be a plain or valley (rather than a mountain), however, this battleground can be contrasted against the heavenly realm of Mount Zion.
The 7th bowl is poured out into the air, showing its reach across the whole world. Thunder, lightening, and earthquake point to Mount Sinai (Exodus 19:16). The great city could speak of Rome or Babylon, or even old Babylon, even Jeruselum is in the mix. With Babylon the Great following later in this chapter, it would point to Babylon as the code for Rome. It is this that is split into three, having drunk the cup of God's wrath. Hail, another link to the Exodus plagues shows us that hail of this size would kill anyone and everyone who is unprotected from it. This hail would cover the earth, killing all those that are unwilling to repent.
So how do we interpret this chapter? In many aspects, this is playing on the theme we've already seen over the course of the book so far. God is sovereign and everything happens under His watch. God's people will be protected from these judgements, while those that fail to repent and turn to God will experience the fullness of God's just and holy wrath.