Babylon has fallen, 1-3. The people of God commanded to depart out of her, 4-8. The kings of the earth, with the merchants and mariners, lament over her, 9-19. The saints rejoice for the judgments of God upon her, 20-24.
1 And after these things, I saw another angel come down from heaven having great power, and the earth was lightened with his glory. 2 And he cried mightily with a strong voice, saying, "Babylon the great has fallen, has fallen, and has become the habitation of demons, the hold of every foul spirit, and a cage of every unclean and hateful bird. 3 For all nations have drank of the wine of the wrath of her lewdness, the kings of the earth have committed lewd deeds with her, and the merchants of the earth have become rich through the abundance of her delicacies."
4 And I heard another voice from heaven, saying, "Come out of her, my people, so that you are not partakers of her sins and that you do not receive of her plagues. 5 For her sins have reached to heaven, and God has remembered her iniquities. 6 Reward her even as she rewarded you, and double to her double according to her works. In the cup which she has filled, fill to her double. 7 However much she has glorified herself and lived deliciously, in such amount give her torment and sorrow, for she says in her heart, '"I sit as a queen," "I am not a widow, and never shall I see sorrow."' 8 Therefore, her plagues shall come in one day: death, mourning, and famine. And she shall be utterly burned with fire, for the Lord God who judges her is strong.
9 "And the kings of the earth who have committed lewdness and lived deliciously with her shall bewail her and lament for her when they see the smoke of her burning, 10 Standing afar off for the fear of her torment, saying, 'Alas, alas, that great city Babylon, that mighty city! For in one hour your judgment has come.'
11 "And the merchants of the earth shall weep and mourn over her because no man buys their merchandise anymore: 12 The merchandise of gold, silver, precious stones, of pearls, fine linen, purple, silk, scarlet, all thyine wood, all vessels of ivory, all vessels of most precious wood, of brass, iron, marble, 13 Cinnamon, odors, ointments, frankincense, wine, oil, fine flour, wheat, beasts, sheep, horses, chariots, slaves, and souls of men. 14 And the fruits that your soul lusted after have departed from you, and all things which were dainty and splendid have departed from you, and you shall no longer find them at all. 15 The merchants of these things who were made rich by her shall stand afar off because of the fear of her torment, weeping and wailing, 16 And saying, 'Alas, alas, that great city that was clothed in fine linen, purple, and scarlet, and decked with gold, precious stones, and pearls! 17 For in one hour such great wealth has come to nothing.' And every ship-master and all the company in ships, along with sailors and as many as trade by sea, stood afar off, 18 And cried when they saw the smoke of her burning, saying, 'What city is like this great city?' 19 And they cast dust on their heads and cried, weeping and wailing, saying, 'Alas, alas, that great city in which all who had ships in the sea were made rich by reason of her opulence!' For in one hour she is made desolate. 20 Rejoice over her, O heaven, and you holy apostles and prophets, for God has avenged you on her."
21 And a mighty angel took up a stone like a great millstone and cast it into the sea, saying, "Thus with violence that great city Babylon shall be thrown down and shall no longer be found. 22 And the voice of harpers, musicians, of pipers, and trumpeters shall no longer be heard in you. No craftsman of any craft shall be found in you anymore. The sound of a millstone shall no longer be heard in you. 23 The light of a candle shall no longer shine in you. The voice of the bridegroom and of the bride shall no longer be heard in you. For your merchants were the great men of the earth, because by your sorceries all nations were deceived. 24 And in her was found the blood of prophets, of saints, and of all who were slain upon the earth."
Matthew Henry Commentary - Revelation, Chapter 18[➚]
[v.7] - Quoting Isaiah 47:7-8.
[v.20] - Christians are to rejoice in God's deliverance and salvation and give Him the praise. Reference, Exodus 15:1, 21; Judges 5:2; 1st Samuel 2:1; Psalm 9:14, 13:5, 20:5, 35:9, 51:15, 71:8, 118:14; Isaiah 12:2-3; Habakkuk 3:18; Luke 1:46-47; Philippians 4:4; 1st Peter 1:8-9.