And the sixth angel sounded his trumpet; and I heard a voice from the four horns of the golden altar which is before God… saying to the sixth angel: “Release the four angels who are bound at the great river Euphrates.” And the four angels who had been prepared for the hour and day and month and year, were released, that they might kill a third of humankind. And the number of the army of horsemen was two hundred million; I heard the number of them.

And thus I saw the horses in the vision and those sitting upon them, having breastplates of fire and hyacinth and sulphur; and the heads of the horses were as heads of lions, and from their mouths were coming fire and smoke and sulphur. From these three plagues were killed a third of humankind…for the authority of the horses is in their mouths and in their tails… they cause harm.

And the rest of the people, not killed by the plagues, did not repent…so as not to worship the demons and the idols of gold, silver, brass, stone, and of wood…they did not repent of their murders, sorceries, fornication or thefts. Revelation 9: 13-21

The voice heard from the golden altar, in all likelihood, is that of Jesus instructing the angel to sound its trumpet. As such, four angels will be released. These four angels are different from the four angels that restrained and released the four winds. These four angels, themselves, are being released. 

Here, the river Euphrates should be thought of as it is Rev. 16: 12; that is in the figurative sense. In the historical, literal sense, the river was the domain of Babylon. And so it is here; the symbolic domain of mystical Babylon, or I should say Wormwood. So within this domain are  four angels, which are not of God; for as the next few verses will show, these angels are angry and very much eager to perpetrate evil; whereas the “four winds angels” patiently protected the earth from destruction.

The Euphrates is where Abaddon unleashed his five months of torment. And now that the torment is over; it is not forgotten. In fact, there is furious resentment about it. So the four angels, representing Wormwood’s human agents; at the appropriate time go forth to retaliate.

And John hears the number of them. It is an organized military force of two hundred million. Then John sees the army– horses and riders. Being more strange than the locusts, these are no ordinary horses. Furthermore, the breastplate colors of the demonic horsemen – red, smoky blue and sulphurous yellow – align with the fire, smoke, and brimstone that blow forth from their horses’ mouths, which is what kills a third of mankind.

This chapter is a parallel to Dan. 11: 40’s speaking of the end time, wherein the king of the south annoyed the king of the north. Then the king of the North retaliated and overpowered the king of the south. In this case, it is Abaddon’s people (pale horse) who after having tormented Wormwood’s people (red horse), a third of them are now being killed. It should be noted that when “thirds” are mentioned throughout Rev., it is a number indicative of that under Satan’s dominion.

Afterwards, there are those who survive in Abaddon’s camp; for only a third of them are killed. Amazingly, the survivors continue to participate in their pagan religion of idols and sorcery; the religion headed by Abaddon. For one would think that they would be resentful of Abaddon for not allowing them to kill Wormwood’s people when they had the chance. Instead, they do not turn away from him. Whether it is out of fear or loyalty, they relentlessly pursue evil living.

This is the second “woe.” And the whole of the matter is that it is Satan — as  both Wormwood and Abaddon —  who sets up  this war between his own people.