The common feature between the sixth trumpet and the sixth bowl is the great river Euphrates (v. 12; compare 9:14). Here, instead of 200 million cavalry (9:16-17), John sees the kings from the East coming across the Euphrates (v. 12), representing the kings of the whole world assembled for a great battle (v. 14). These kings and their armies correspond to the cavalry of the earlier vision and, like those demonic forces, bring trouble to the earth in threes: three plagues of fire, smoke and sulfur in the earlier instance (9:18), and here three evil spirits that looked like frogs; they came out of the mouth of the dragon, out of the mouth of the beast and out of the mouth of the false prophet (v. 13). The comparison between these spirits and frogs is the only link between this plague and the Exodus (see Ex 8:1-15).
The evil spirits of this verse are literally "unclean spirits," the same phrase used in the Gospel of Mark for demons (see, for example, Mk 1:23; 5:2). John, after telling what he saw (v. 13), now speaks as a prophet to confirm the identification of the spirits as spirits of demons performing miraculous signs, and to interpret kings from the East as the kings of the whole world (v. 14). John transforms the Roman fear of Parthian invaders (see 9:14) into a universal confrontation. To him, kings and nations and armies are demon possessed, not just individuals. Twice he states that the evil spirits "gathered them" for battle (vv. 14, 16), giving first the time and then the place of the great final conflict. The time is the great day of God Almighty (v. 14), and the place is the place that in Hebrew is called Armageddon (v. 16). In giving the time, John gives away the outcome as well. The great day of God Almighty means the day on which God Almighty is victorious. There is no suspense about how the battle will turn out, and further glimpses of it in subsequent chapters (17:14; 19:17-21) will only confirm the inevitable.
Between the notation of the time (v. 14) and place (v. 16) of the battle, John's prophetic voice suddenly gives way to the voice of Jesus himself (v. 15). It is the first time Jesus has spoken directly since dictating the seven messages of chapters 2 and 3, and his words sound very much like words from those messages: Behold, I come like a thief! Blessed is he who stays awake and keeps his clothes with him, so that he may not go naked and shamefully exposed (v. 15; compare 3:2-4, 18). This word of warning to the book's readers comes very abruptly in its context. Probably the reference to the great day of God Almighty (v. 14) suggested the image of "the day of the Lord," which in early Christian instruction was said to come "like a thief in the night," a tradition known to both Paul and his readers in 1 Thessalonians 5:2 (compare also Mt 24:43 and Lk 12:39). For John's readers the words represent a hopeful time shift from that near future day, when, too late for repentance, the world moves inexorably to its doom, back to a present in which there is still time to "Wake up! Strengthen what remains and is about to die," so as to walk with Jesus "dressed in white" (3:2, 5). When Armageddon comes, the day of grace will be over. Either we are on God's side--the victorious side--or we perish with those who are deceived by the dragon, the beast and the false prophet.
The word Armageddon conjures up twentieth-century images that are mostly foreign to the book of Revelation--above all the image of global nuclear war. The term in its immediate context refers not to a battle but to a place, whether fictional or real. Armageddon, or "Harmagedon" (NRSV), was as strange to the book's original readers as it is to us today. It is a Hebrew name in a Greek book and, unlike the Hebrew name "Abaddon" (9:11), is given in Hebrew only, without a Greek translation. The first syllable, har, is the Hebrew word for "mountain," so that the name could be read "mountain of Mageddon" or "mountain of Megiddo."
In the Hebrew Bible, Megiddo was the name of a fortified city and a plain in northern Palestine. The plain of Megiddo was strategically located, a kind of natural battlefield and the scene of one notably disastrous battle, the defeat of King Josiah at the hands of Pharaoh Neco of Egypt (2 Kings 23:29-30; 2 Chron 35:20-24). "Megiddo" may have had connotations similar to "Waterloo" in a more modern setting. But there was no Mount Megiddo nor any mountain near Megiddo. "Harmagedon," or "mountain of Megiddo," therefore, is a contradiction. It is as if we said today that a great battle would take place at "Death Valley Mountain." The strange name may have been chosen deliberately to signal that the place was imaginary, not real, and that the great final "battle" would not be an actual battle at all. In any case, no battle is described in connection with the pouring out of the sixth bowl. Troops are assembled, but nothing happens.