Someone might be wondering, but how can Babylon represent the world? I thought it represented the church?
Let's think about this historically, when the ancient nation of Babylon came against the nation of Judah and conquered it. The Jews were carried to Babylon. The Babylonians left a remnant of people in the land of Judah and set up a governor over it.Due to rite of conquest, the nation of Judah became a province of the nation of Babylon. It (Judah) became Babylon in that sense. But it belonged to a greater entity also known as Babylon.
Likewise, Satan's kingdom came against the N.T. churches and overcame them (Revelation 13:6,7) therefore the churches became a part or a province of Satan's overall kingdom.After the period of judgment on the churches concluded---then God turned around and judged the greater entity of Babylon. The overall kingdom of Satan (which includes the newly conquered province of the corporate church)--which is the entire world.
So, insofar as the church was conquered by Babylon, it became a part of that evil nation. But Babylon as a whole represents the complete kingdom of Satan which is this world and all of its unsaved inhabitants.