In Revelation 18:20 the righteous are told to rejoice over the fall of Jerusalem (cp. Psalm 96:11-13), and this includes the slain Apostles and prophets that the Lord had sent to her (Luke 11:49-50). At long last, judgment had come, and the righteous had been vindicated (Revelation 6:9-11). The seventh bowl of the Lord’s wrath was poured out “into the air,” and it was done (Revelation 16:17). Prior to the pouring out of the seventh vial, it was dangerous for the righteous to speak into the air (Ephesians 2:2), whose tension or spirit was controlled by the children of disobedience! The dangerous environment, which the Jewish authorities had created for Jesus’ disciples, had turned back upon them. Now, they were slain and taken captive. Now, they were persecuted and died of famine and pestilence. The air had suddenly changed, for Jesus had returned and the righteous were caught up together …in clouds, to meet the Lord in the air” (1Thessalonians 4:17)!
The righteous were suddenly and abruptly taken out of the air (aer – G190; Revelation 16:17; 1Thessalonians 4:17) of persecution and wickedness and rose in clouds to meet the Lord in the air, the new air of peace and safety, wherein they could preach the Gospel unhindered and meet together without fear. One might compare this with Acts 2:2 where Jesus’ disciples were suddenly and abruptly taken out of the world of the flesh and put into the realm of the Spirit. The Lord descended and his people were snatched out of the dangerous air created by the Jerusalem authorities and placed into a new and peaceful realm, a different air (aer G190) saturated with a different power made different by a new law, which benefited all those who were found in Christ (cp. 1Thessalonians 4:17).
Suddenly, there was reason for the righteous to rejoice (Revelation 18:20), because no one hounded their steps, and they were suddenly free of fear (Proverbs 11:10). They had been vindicated, and the wicked were taken out of the way (Psalm 107:42; Matthew 16:27-28). As an echo of Jeremiah 51:63-64, the mighty angel claimed that with violence Babylon shall be thrown down (into the sea / into the world – Revelation 18:21) and be found no more. Moreover, in Revelation 18:22-23 the angel described the judgment of the great harlot in terms of not having any reason to rejoice. No longer would there be musicians or songs sung during her feasts, nor would there be the sound of craftsmen creating new and wonderful works, nor would there be sound of the millstone grinding out grain for food. Not even a candle would be lit there, nor would a man and a women ever marry there again, because Jerusalem (Babylon) was destroyed.
The Jerusalem of today is actually built on top of the rubble of the Lord’s judgment of 70 AD. In the words of one of Israel’s modern poets:
“Jerusalem is like an Atlantis that sank into the sea everything there is submerged and sunken This is not the heavenly Jerusalem but the one down below, way down below. And from the sea floor they dredge up ruined walls and fragments of faiths, like rust-covered vessels from sunken prophecy ships. That’s not rust, it’s blood that has never dried” (Yehuda Amichai, 1998).
Why was Jerusalem judged so harshly? In the words of the mighty angel it was because: “your merchants were the great men of the earth; for by your sorceries were all nations deceived” (Revelation 18:23)! That is, the merchants, the rabbis and Jewish evangelists, who traveled the Empire seeking disciples, made all who embraced Jerusalem’s worldview twice the child of hell their teachers were (Matthew 23:15). The New Covenant Scriptures record two major persecutions and Josephus mentions a third—all at the hands of Jerusalem, and such things were predicted by the Lord, and he laid the fault for those crimes at the feet of the Jerusalem authorities (Matthew 23:34-36; Revelation 18:24).
 See Acts 8:1-3; 11:19 for the first; and Acts 12:1-4 for the second – Peter and the surviving Apostles had to flee Agrippa’s realm.
 See Antiquities of the Jews 20.9.1 where the final persecution began with the death of James, the Lord’s brother.