Revelation 16:14-16

for they are [actually] the spirits of demons, performing [miraculous] signs. And they go out to the kings of the entire inhabited earth, to gather them together for the war of the great day of God, the Almighty. (“Behold, I am coming like a thief. Blessed is he who stays awake and who keeps his clothes [that is, stays spiritually ready for the Lord’s return], so that he will not be naked—spiritually unprepared—and men will not see his shame.”) [Matt 24:42-44; 1 Thess 5:2-4] And they (demons) gathered the kings and armies of the world together at the place which in Hebrew is called Har-Magedon (Armageddon).