Revelation 14:7-8

Revelation 14:7-8. For the hour of his judgment is come: and worship him that made heaven, and earth, and the sea, and the fountains of waters. And there followed another angel, saying, Babylon is fallen, is fallen,

This will not happen till the gospel is fully preached. Superstition does not come down unless true religion is set up. One angel proclaims the everlasting gospel; the next declares that the great system of error is fallen: "Babylon is fallen."