Read Revelation 18.
The judgment that was prophesied for Babylon in chapter 17 was described here in Revelation 18. Nothing specific is detailed about her demise; instead, it was described by angels then mourned by men on earth. But, before he destroyed Babylon, God warned his people to flee it so that they would be delivered from his judgment (vv. 4-8).
There are unbelievers in our world who object to our message by pointing to what they call the genocide of the God of the Old Testament. What is often missed, however, is that God routinely warns the wicked before he brings judgment on them. He warned the world through Noah before the flood, he warned Lot and his family before Sodom was consumed, he warned Ninevah through Jonah, Nebuchdnezzar in Daniel, and so many others. Although God is just when he judges humanity, even his justice is tempered by mercy because he warns people to repent and flee his wrath. Keep this in mind when people object to the gospel, particularly the doctrine of hell. God told us about hell so that we would fear him and receive his grace in Christ to avoid it.
In fact, part of the message of Christmas is that God came down into our world to warn us of his coming judgment and deliver us from that wrath in Christ. As we give thanks for Christ at Christmas time, let’s remember to look for opportunities to warn others around us and show them how to escape God’s judgment through our Lord Jesus Christ.