I am amazed at how lack of Bible study some folks are about what the Revelation Mystery Babylon is. It is a CITY per God's Word...
Rev 17:3-6
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.
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:
5 And upon her forehead was a name written, MYSTERY, BABYLON THE GREAT, THE MOTHER OF HARLOTS AND ABOMINATIONS OF THE EARTH.
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.
KJV
Rev 17:18
18 And the woman which thou sawest is that great city, which reigneth over the kings of the earth.
KJV
Rev 11:8
8 And their dead bodies shall lie in the street of the great city, which spiritually is called Sodom and Egypt, where also our Lord was crucified.
KJV
The new Jerusalem is also called "that great city" (Revelation 21:10). So is she a harlot too? Or is the harlot the antithesis of the great city, New Jerusalem?
New Jerusalem "that great city":
And one of the seven angels who had the seven vials full of the seven last plagues came to me and talked with me, saying,
Come here, I will show you the bride, the Lamb's wife. (Revelation 21:9)
Babylon the Great "the great city":
And one of the seven angels who had the seven vials came and talked with me, saying to me,
Come here, I will show you the judgment of the great harlot sitting on many waters. (Revelation 17:1).
New Jerusalem is a city of gold, precious stones and pearls (Revelation 21:10-11 & 18-21).
The harlot is "..gilded with gold, precious stones and pearls, having a golden cup in her hand full of abominations and filthiness of her FORNICATION" (Revelation 17:4).
The ruler of the faithful kings of the earth is Christ (Revelation 1:5), i.e Christ rules over New Jerusalem.
The harlot city rules over ALL the kings of the earth who commit fornication with her (Revelation 17:2).
New Jerusalem, that great city (Revelation 21:10) is not a city with physical dimensions but is populated by people of all nations, tribes and tongues, and is spiritual:
Hebrews 12
22 But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to an innumerable company of angels,
23 to the general assembly and church of the first-born who are written in Heaven, and to God the judge of all, and to the spirits of just men made perfect,
24 and to Jesus the Mediator of the new covenant, and to the blood of sprinkling that speaks better things than that of Abel.
So we could say therefore that
"Those who do not read the scriptures or only believe part of what they read believe that the antithesis of New Jerusalem is a city with a physical boundary that is NOT comprised of all nations, tribes and tongues, just because it's called "the great city" (even though Revelation 13 tells us that the beast will reign over all nations, tribes and tongues; and the Revelation calls Babylon the Great a harlot that fornicates with the beast.)"
Should we now say that we are amazed at how through lack of Bible study some folks are ignorant about what the Revelation's Great Cities, New Jerusalem and Babylon the Great are talking about?
Well, we COULD - but perhaps we should just all stop putting ourselves forward as know-it-alls and admit that we do not always know what we are talking about. Babylon the Great is the antithesis of New Jerusalem whose King is Christ, who rules over the (faithful) kings of the earth.
And as such there is no evidence in the Revelation that Babylon the Great has the physical boundaries of A city on earth. Revelation suggests and implies that it's IN the world, just like the antithesis, that great city, New Jerusalem is already IN the world.
There is no evidence in the Revelation for Babylon the Great being either Jerusalem of the Jews or The Vatican or any other city with physical boundaries unless someone chooses to ADD that to the Revelation. All the Revelation is doing is contrasting the bride of Christ and the harlot by way of a thesis-antithesis comparison.