Revelation Chapter 15
The seven angels, with the last seven plagues, will then prepare to complete The Seven Seals; the seventh seal has seven trumpets, the seventh trumpet has seven "vials" or "bowls." At this point, all that remains to be delivered are the seven vials, "the seven last plagues." Amidst all of those events, The Return Of Jesus Christ and the first resurrection (see To Meet The Lord In The Air) will occur.
"15:1 And I saw another sign in heaven, great and marvellous, seven angels having the seven last plagues; for in them is filled up the wrath of God. 15:2 And I saw as it were a Sea of Glass mingled with fire: and them that had gotten the victory over the beast, and over his image, and over his mark, and over the number of his name, stand on the sea of glass, having the harps of God.
15:3 And they sing the song of Moses the servant of God, and the song of the Lamb, saying, Great and marvellous are thy works, Lord God Almighty; just and true are thy ways, thou King of saints [see What Is A Saint?]. 15:4 Who shall not fear thee, O Lord, and glorify thy name? for thou only art holy: for all nations shall come and worship before thee; for thy judgments are made manifest [see When Will You Be Judged?].
15:5 And after that I looked, and, behold, the temple of the tabernacle of the testimony in heaven was opened: 15:6 And the seven angels came out of the temple, having the seven plagues, clothed in pure and white Linen, and having their breasts girded with golden girdles. 15:7 And one of the four beasts gave unto the seven angels seven golden vials full of the wrath of God, who liveth for ever and ever [see The Ancient of Days]. 15:8 And the temple was filled with smoke from the glory of God, and from his power; and no man was able to enter into the temple, till the seven plagues of the seven angels were fulfilled." (Revelation 15:1-8 KJV)
Revelation Chapter 16
The seven vials will bring about the fall of Satan's world, the fall of "Babylon," a word that in the original Hebrew means confusion. Within the time of the seven vials will be the famous "battle of Armageddon" which will actually not be great armies of man against each other, but the armies of man against Christ (see The Battle of Armageddon).
"16:1 And I heard a great voice out of the temple saying to the seven angels, Go your ways, and pour out the vials of the wrath of God upon the earth.
16:2 And the first went, and poured out his vial upon the earth; and there fell a noisome and grievous sore upon the men which had the mark of the beast, and upon them which worshipped his image.
16:3 And the second angel poured out his vial upon the sea; and it became as the blood of a dead man; and every living soul died in the sea.
16:4 And the third angel poured out his vial upon the rivers and fountains of waters; and they became blood. 16:5 And I heard the angel of the waters say, Thou art righteous, O Lord, which art, and wast, and shalt be, because thou hast judged thus. 16:6 For they have shed the blood of Saints and Prophets, and thou hast given them blood to drink; for they are worthy. 16:7 And I heard another out of the altar say, Even so, Lord God Almighty, true and righteous are thy judgments.
16:8 And the fourth angel poured out his vial upon the sun; and power was given unto him to scorch men with fire. 16:9 And men were scorched with great heat, and blasphemed the name of God, which hath power over these plagues: and they repented not to give him glory.
16:10 And the fifth angel poured out his vial upon the seat of the beast; and his kingdom was full of Darkness; and they gnawed their tongues for pain, 16:11 And blasphemed the God of heaven because of their pains and their sores, and repented not of their deeds.
16:12 And the sixth angel poured out his vial upon the great river Euphrates; and the water thereof was dried up, that the way of the kings of the east might be prepared. 16:13 And I saw three unclean spirits like frogs come out of the mouth of the dragon [i.e. Satan; see Dragons], and out of the mouth of the beast [i.e. the last leader of the last revival of the Roman Empire; see Emperor], and out of the mouth of the false prophet [i.e. the last pope; see Emperors and Popes]. 16:14 For they are the spirits of Devils, working miracles, which go forth unto the kings of the earth and of the whole world, to gather them to the battle of that great day of God Almighty.
16:15 Behold, I come as a thief. Blessed is he that watcheth, and keepeth his garments, lest he walk naked, and they see his shame [see Could Christ Return Tonight?].
16:16 And he gathered them together into a place called in the Hebrew tongue Armageddon.
16:17 And the seventh angel poured out his vial into the air; and there came a great voice out of the temple of heaven, from the throne, saying, It is done. 16:18 And there were voices, and thunders [see Thunder], and lightnings [see also Lightening, Not Lightning]; and there was a great earthquake [see Earthquake!], such as was not since men were upon the earth, so mighty an earthquake, and so great. 16:19 And the great city was divided into three parts, and the cities of the nations fell: and great Babylon came in remembrance before God, to give unto her the cup of the wine of the fierceness of his wrath. 16:20 And every island fled away, and the mountains were not found. 16:21 And there fell upon men a great hail out of heaven, every stone about the weight of a talent: and men blasphemed God because of the plague of the hail; for the plague thereof was exceeding great." (Revelation 16:1-21 KJV)
Revelation Chapter 17
The true Church of God is sometimes described as a woman (see The Two Women of Creation); the false Christian-professing "church" is described, in this chapter, and elsewhere, as a great harlot (i.e. the Church of Rome which has committed spiritual adultery - see Thou shalt not commit adultery to understand the ultimate purpose and meaning of the Commandment) and mother of harlots (i.e. the many daughter "Protestant" churches that came away from, but not truly out of, the Church of Rome, because they continue the same doctrines e.g. see Sun Worship).
The Great Tribulation is primarily about true Christians being persecuted by people who merely think that they are Christian: "17:6 And I saw the woman drunken with the blood of the saints, and with the blood of the martyrs of Jesus" (Revelation 17:6 KJV). The good news is that the deceived people will one day wake up and turn on the false churches that have deceived them: "17:15 And he saith unto me, The waters which thou sawest, where the whore sitteth, are peoples, and multitudes, and nations, and tongues. 17:16 And the ten horns which thou sawest upon the beast, these shall hate the whore, and shall make her desolate and naked" (Revelation 17:15-16 KJV).
Keep in mind that the chapters of Revelation are not strictly chronological in order; inset chapters describe, in greater detail, events or prophecies that are stated in other chapters e.g. the seven seals, although they will happen in a consecutive order without interruption, are recorded across Revelation chapters 6, 8, 9 and 16.
"17:1 And there came one of the seven angels which had the seven vials, and talked with me, saying unto me, Come hither; I will show unto thee the judgment of the great whore that sitteth upon many waters: 17:2 With whom the kings of the earth have committed fornication, and the inhabitants of the earth have been made drunk with the wine of her fornication.
17:3 So he carried me away in the spirit into the wilderness: and I saw a woman sit upon a scarlet coloured beast, full of names of blasphemy, having seven heads and ten horns. 17:4 And the woman was arrayed in purple and scarlet colour, and decked with gold and precious stones and pearls, having a golden cup in her hand full of abominations and filthiness of her fornication: 17:5 And upon her forehead was a name written, Mystery, Babylon The Great, The Mother Of Harlots And Abominations Of The Earth.
17:6 And I saw the woman drunken with the blood of the saints, and with the blood of the Martyrs of Jesus: and when I saw her, I wondered with great admiration.
17:7 And the angel said unto me, Wherefore didst thou marvel? I will tell thee the mystery of the woman, and of the beast that carrieth her, which hath the seven heads and ten horns. 17:8 The beast that thou sawest was, and is not; and shall ascend out of the bottomless pit, and go into perdition [see Sons Of Perdition In Prophecy]: and they that dwell on the earth shall wonder, whose names were not written in the book of life [see Who Is In The Book Of Life?] from the foundation of the world, when they behold the beast that was, and is not, and yet is.
17:9 And here is the mind which hath wisdom. The seven heads are seven mountains, on which the woman sitteth. 17:10 And there are seven kings: five are fallen, and one is, and the other is not yet come; and when he cometh, he must continue a short space. 17:11 And the beast that was, and is not, even he is the eighth, and is of the seven, and goeth into perdition.
17:12 And the ten horns which thou sawest are ten kings, which have received no kingdom as yet; but receive power as kings one hour with the beast. 17:13 These have one mind, and shall give their power and strength unto the beast. 17:14 These shall make War With The Lamb, and the Lamb shall overcome them: for he is Lord of lords, and King of kings: and they that are with him are called, and chosen, and faithful.
17:15 And he saith unto me, The waters which thou sawest, where the whore sitteth, are peoples, and multitudes, and nations, and tongues. 17:16 And the ten horns which thou sawest upon the beast, these shall hate the whore, and shall make her desolate and naked, and shall eat her flesh, and burn her with fire. 17:17 For God hath put in their hearts to fulfil his will, and to agree, and give their kingdom unto the beast, until the words of God shall be fulfilled. 17:18 And the woman which thou sawest is that great city, which reigneth over the kings of the earth." (Revelation 17:1-18 KJV)
Fact Finder: What has been the history of the place called "Armageddon"?
See Countdown To Armageddon