The Eternal, in his mercy, has chosen to divulge major aspects of each upcoming battle the devil will wage against him and his way of life.
Scripture tells us the exact locations from which the devil will launch each of his three vicious attacks (heaven, the valley of Megiddo and the last one near Jerusalem). The Bible also reveals the time each offensive move of the devil will take place (just before the Great Tribulation, at the end of the Beast's forty-two month rule of the earth and at the end of the Millennium).
Additionally, the Bible informs us who the devil will fight against in each of his attempts to seize power (righteous angels, a returning Jesus Christ with his saints, the inhabitants of Jerusalem).
Lastly, the outcome of each battle in the devil's war against righteousness has also been foretold (his demonic army will lose their final conflict in heaven, his forty-two month reign of terror on the earth will be stopped and his efforts to conquer Jerusalem halted with eternal fire).
Last Heavenly Battle
Satan, who is as perfect at being evil as God is at being good, will soon launch what will become his final spiritual battle within heaven. It will commence just before his rule of the earth through the Beast and the False Prophet. Unlike his first attempt at seizing power, however, God will not be directly involved in the battle. This time, an army of righteous angels, led by the archangel Michael, will fight against the enemy.
God's angels will ultimately be victorious over the devil and his spiritually evil army. He and his sinful companions will not only be thrown back to earth a second time, they will be barred from ever returning to heaven (Revelation 12:7 - 9). The prince of darkness will become so enraged at his permanent ejection that he will implement his plan to rule humans as a god.
And there was war in heaven; Michael and his angels warred against the dragon, and the dragon and his angels warred.
But they did not prevail, neither was their place found any more in heaven. And the great dragon was cast out, the ancient serpent who is called the Devil and Satan, who is deceiving the whole world; he was cast down to the earth, and his angels were cast down with him . . .
Therefore, rejoice you heavens and those who dwell in them. Woe to those who inhabit the earth and the sea! For the Devil has come down to you, having great wrath because he knows that he has only a short time. (Revelation 12:7 - 9, 12, HBFV, see also chapter 13).
The third offensive the devil will lead is called "the battle of that great day of the Almighty God" (Revelation 16:14, HBFV) or, more commonly, the battle of Armageddon (verse 16). It takes place entirely on the earth at the valley of Jezreel (Megiddo).
Satan, through the Beast and False Prophet, as well as the help of other demons, will gather humans to fight a returning Jesus Christ (Revelation 16:12 - 16, 17:14 - 18, 19:17 - 21). Jesus' righteous army will be composed primarily of resurrected saints who will be allowed to govern the earth with him for 1,000 years (20:4, 6).
After the prophecied battle is decisively won by the Lord and his army, a powerful angel will grab the great deceiver and throw him into a spiritual prison cell until the Millennium is completed.
Then I saw an angel descending from heaven, having the key of the abyss, and a great chain in his hand. And he took hold of the dragon, the ancient serpent, who is the Devil and Satan, and bound him for a thousand years.
Then he cast him into the abyss, and locked him up, and sealed the abyss over him, so that he would not deceive the nations any longer until the thousand years were fulfilled; and after that it is ordained that he be loosed for a short time. (Revelation 20:1 - 3, HBFV).
The Last Conflict
The final spiritual battle in the war between good and evil will take place entirely on the earth. The devil will be let out of his millennial prison and one last time be allowed to gather an army. He will quickly deceive as many humans as he can and then march them toward Jerusalem, earth's capital city. It is from the city that Christ and his resurrected saints have ruled humanity for 1,000 years.
Now when the thousand years have been completed, Satan shall be loosed out of his prison; And he shall go out to deceive the nations that are in the four corners of the earth, Gog and Magog, of whom the number is as the sand of the sea, to gather them together for war.
Then I saw them go up upon the breadth of the earth and encircle the camp of the saints, and the beloved city; and fire came down from God out of heaven and consumed them (Revelation 20:7 - 9, HBFV).
God will protect his holy city by sending fire from heaven to consume those surrounding it. The devil, for the last time, will be captured. He will then, as the originator of sin in the universe and the deceiver of mankind, receive the penalty he justly deservers. He will be thrown into the lake of fire where his existence will end.