In chapters 17-19 John presents Heaven’s explanation of the vision of angels pouring out the “vials”/bowls of God’s wrath. The angel introduced in 17:1 establishes that what John now sees is a depiction of judgement that bears out the “beginning of the end” theme that began with emptying of those bowls in chapters 15-16.
Chapter 17 paints a picture that most biblical scholars with pagan Imperial Rome – the judgement of the “Great Harlot.” This chapter falls naturally into two parts; the “harlot” is described in vv. 1-6, and the symbols that identify her (to John) are explained in vv 7-18. The exclamation in vs. 9 – “Here is the mind that hath wisdom” – is a way of telling the reader (especially first-century readers), “Here is a clue!” to understanding what John sees. The angel here, who summons John to view the judgement of the harlot, will also be the one who shows him the Lamb’s bride in Revelation 21:9. (This contrasts the corruption of the harlot with the purity of the bride.)
The Greek word for “harlot” (whore in most English bibles) is por-nay, the root of the word “fornication” in our English translations. This connection takes us back to Revelation 14:8, where the fall of Babylon was announced, with the reason for her fall being her fornication. This figure is never described in the Revelation as an adulteress (R.C.H. Lenski points out that, “…she was never [the] bride or wife of the Lamb….” In essence, everything about her is defiled and unclean; she has NO redeeming qualities.
The message of the angel who speaks in Revelation 18 adds detail to the picture of judgement in chapter 17 – it is a merciless dirge that shows “Babylon” as a city now utterly prostrated by perversion. John’s description here borders on melodrama, to emphasize the catastrophe he sees befalling the great city; even as her judgement is being carried out, her people “mourn” the loss of opportunities to continue feeding their lusts (not the loss of their opportunity for salvation)! At the end of vs. 13 John mentions the “souls of men” as a “commodity” for which there is no longer a market. This expression represents the very lives of individuals and calls to mind both Rome’s traffic in (and cruel use of) slaves, AND the fact that the lives of slaves were nothing more than living entertainment to such jaded and depraved people; their lives, sufferings, and deaths in the coliseum served only to amuse others.
The “Hallelujah Chorus” of chapter 19 prepares us for the final victory of God and His people over the power, persecution and persistence of Satan and his evil allies. The scenes John sees and records here set the stage for the ultimate declaration of judgement in chapter 20. The praises he hears are the response to the instruction in Revelation 18:20 (and vv. 1, 3, 4, & 6 are the only times in the new testament where the expression “Hallelujah” is found). There is a dramatic contrast in attitude between chapters 18 and 19; the scenery and “soundtrack” change from a dirge to celebration, from sorrow and suffering to joy and rejoicing.
The later part of this chapter describes the Lord’s appearance as Judge, and the capture of the beast and the false prophet so they can be cast into the sulfurous lake. All others who chose to follow them — who gathered to resist the Lamb — are “slain” (sentenced, cf. John 12:48) by His word, vs. 21.