War breaks out in heaven, and Satan is thrown down by the archangel Michael and his allies. This great conflict occurs after the Messiah is taken up to God's throne. It was understood that Satan once was able to make accusations against people before God (Job 1:6-12), but after Christ's death, resurrection, and ascension, Satan has been barred from the heavenly throne room. Moreover, the vision shows that Satan lashes out on the earth because he is angry at having lost out in heaven. Satan is like a caged animal who tries to do as much damage as possible in the space he has available. Evil is present and active on earth, but it is not all-powerful.
According to some Christian traditions, Satan rebelled against God and was thrown out of heaven at the beginning of time. This is a way of explaining how evil came into the world that was created to be good. For some, it accounts for the presence of the serpent who tempted Eve in the Garden of Eden. The story of Satan's fall at the beginning of time is not actually found in the Bible, although it is based in part on Isaiah 14:12-15, which compares an arrogant tyrant to a star falling from heaven.
7 And war broke out in heaven; Michael and his angels fought against the dragon. The dragon and his angels fought back, 8but they were defeated, and there was no longer any place for them in heaven. 9The great dragon was thrown down, that ancient serpent, who is called the Devil and Satan, the deceiver of the whole worldhe was thrown down to the earth, and his angels were thrown down with him.
10 Then I heard a loud voice in heaven, proclaiming,
Now have come the salvation and the power
and the kingdom of our God
and the authority of his Messiah,*
for the accuser of our comrades* has been thrown down,
who accuses them day and night before our God.
11 But they have conquered him by the blood of the Lamb
and by the word of their testimony,
for they did not cling to life even in the face of death.
12 Rejoice then, you heavens
and those who dwell in them!
But woe to the earth and the sea,
for the devil has come down to you
with great wrath,
because he knows that his time is short!
New Revised Standard Version Bible: Anglicized Edition, copyright © 1989, 1995 National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved worldwide. http://nrsvbibles.org