It should be noted first that in the Greek the idea of “out” (in the sense of “come away”) receives distinct emphasis. God would have his people distance themselves from “her.” The pronoun “her” is a reference to Babylon, that woman of Revelation 17 who had fallen before King Jesus (Revelation 17:14; Revelation 18:2). She was called “Babylon” because Babylon in the Old Testament (as also her earlier namesake Babel) was characterized by that spirit of independence from God, even to the point of trying to dethrone God (see Genesis 11:4; see further Daniel 4:30). Any city or state or civilization in the new dispensation that adopts for herself this self-sufficient, anti-God attitude is “Babylon.” She is adulterous in disposition, which means she seeks to entice (God’s) people to commit spiritual adultery (that is, to seek their happiness and sense of well being not in her Bridegroom but in creaturely stuff). The instruction to “come out of her” is not intended spatially in the sense that God’s people need to physically remove themselves from a city or civilization and relocate to a (metaphorical) island (this would contrast with Genesis 19:15; Jeremiah 50:8; Jeremiah 51:6–7, Jeremiah 51:45; Isaiah 48:20; Isaiah 52:11; Zechariah 2:6f). Instead, the instruction wants God’s people to ensure that they are not infected by the arrogant mindset of the anti-God self-sufficiency that characterizes Babylon. For if they do, they will invariably be guilty of (spiritual) adultery, and thus provoke the Bridegroom’s jealousy.
4 Then I heard another voice from heaven saying, “Come out of her, my people, lest you take part in her sins, lest you share in her plagues;