The great city was split into three parts, and the cities of the nations fell, and God remembered Babylon the great, to make her drain the cup of the wine of the fury of his wrath.
The visions of judgement John has for the city of Babylon the great are horrific. The entire world is caught in the chaos of the events of judgment described here. The sun scorches the earth, then the world is plunged into total darkness. There is war, death, and unimagineable natural catastrophe. And still in the descriptions humanity defies and curses God, refusing to repent (see Revelation 16:9-11). The world is ending and still God is cursed.
God's purposes are directed at the center of world power known in Revelation as "Babylon the great". From this city the beast, false prophet, and antichrist have controlled humanity in the ultimate dictatorship and defied God. From this center of all human sinful activity, the world has been corrupted and God's saints have been targetted and executed systematically. And all the horrific judgment has come to focus on the evil that is Babylon. Even as this world is shaken from massive earthquakes, the leaders still defy God again, assembling a vast army in The Valley of Armageddon (Revelation 16:16).
I believe John's vision describes events yet to be. And this motivates me to respond in two distinct ways. The first way I respond is to fear God and love the grace of the gospel. God's justice is fierce, His wrath on sin is great, and knowing the cross satisfies both makes me want to praise the Lord. My second response is to be gospel-committed in conversation. I want to see people saved from this fate. I want as many as believe Christ to be spared this sort of future. I want to be diligent to live and to tell the good news so that people may find God's mercy and grace in Christ.