Context Summary
Revelation 18:1–8 contains a glorious angel’s pronouncement of doom on Babylon. This Babylon here appears to be a literal physical city, whereas the Babylon described in chapter 17 is a corrupt religious system. The Babylon of chapter 17 was associated with a political system but was not the political power. The Babylon of chapter 18 is the center of a demonic political, commercial, and economic system. The fall of Babylon parallels what happened to the cities of Sodom and Gomorrah (Genesis 19:1–29). Religious Babylon falls in the middle of the tribulation to the delight of kings. Commercial Babylon falls at the end of the tribulation, and kings lament her fall.
For a more detailed summary select the link below.
“Revelation 18:4-5” Bibleref.com
What does Revelation 18:4 mean? | BibleRef.com
Revelation 18:4-5
4 I heard another voice from heaven, saying, “Come out of her, my people, that you have no participation in her sins, and that you don’t receive of her plagues, 5 for her sins have reached to the sky, and God has remembered her iniquities.