In the future, after the years of tribulation and the thousand years of peace, God will release Satan from the “bottomless pit” where he has been imprisoned (Revelation 20:2), and he will get another chance to try to deceive all the people of the world. Astonishingly many people from all over the world will fall for his deception once more and reject Jesus Christ. They will march on Jerusalem once more, and be defeated just as completely as they were before at the battle of Armageddon:
When the thousand years are over, Satan will be released from his prison 8 and will go out to deceive the nations in the four corners of the earth—Gog and Magog—and to gather them for battle.In number they are like the sand on the seashore. 9 They marched across the breadth of the earth and surrounded the camp of God’s people, the city he loves. But fire came down from heaven and devoured them. (Revelation 20:7-9 NIV)
The lesson to learn from this episode is that human beings are inherently wicked, and many will always choose evil over good, and will not repent of their sins. That is why, in the end, the Earth will have to be destroyed, and an end will be made of the human race as we know it. The souls of those who have refused to repent will be cast into the lake of Fire for eternity, but those who have humbled themselves and repented in the name of Jesus Christ spend eternity redeemed, incorruptible, with God.
*Note: You can find out more about the battle of Gog and Magog by reading Ezekiel chapters 38 and 39