This brief paragraph provides John with the first of multiple reactions to the vision of Revelation 17:1–18. This first reaction is effectively God’s own commentary on the meaning of that vision. While John and his readers (ourselves included) might react to that vision with a sense of foreboding (for the world seems so dark), the Lord through his angel presses on his readers that this world is full of divine light—precisely because the woman and the beast are defeated. Here is glorious encouragement for people who feel they are living in darkness (Isaiah 9:2).
In the same vein (and as illustration of the triumph of light), John and his readers must know that demons and spirits are in fact prisoners of the King of kings. Though they may dirty the atmosphere of Christ’s earthly kingdom, they are not the powerbrokers of Planet Earth.
1 Après cela, je vis descendre du ciel un autre ange, qui avait une grande autorité; et la terre fut éclairée de sa gloire.