The battle of Gog and Magog is the last world war that this world will ever see
and essentially it's Satan's last attempt to usurp the authority of God.
Now contrary to popular belief it does not take place before the tribulation
but rather at the end of Christ's millennial reign.
At the inauguration of Christ's earthly rule,
Satan is bound for a thousand years in the bottomless pit.
But at the expiration of those thousand years he's then loose from his prison
and Revelation 20 verse 8 says that he goes out to deceive the nations
which are in the four quarters of the earth Gog and Magog
to gather them together to battle whose number is as the sand of the sea.
Satan and his earthly army then come past the camp of the saints in the beloved city
at which point fire comes down from God out of heaven and devours them.
Satan is then cast into the lake of fire permanently
at which point you have the commencement of the white throne judgment.
One thing that we can learn from the battle of Gog and Magog
is that in spite of having Jesus Christ physically here on this earth
ruling with benevolence there will always be a group of people
who not only reject him but will even join forces with Satan to fight again.