There are two super significant battles that will happen in the future. One happens at the end of this age and the other at the end of the Millennium. There is so much rhetoric and falsehood on this subject, that it is very important to know the truth of what the Bible says in order to avoid being deceived into false concepts.
First of the two final battles, will happen at Armageddon.
Many people say that "Armageddon" can happen at any time and can even be brought on by warring nations. That concept is not biblical. The Battle of Armageddon is about Satan, rallying his demonic forces with human forces against God and His forces. Whereupon Jesus will come from heaven on His white horse with the armies of heaven and conquer and subdue them in short order.
The Battle of Armageddon ends with the Antichrist & false prophet being captured and thrown into the lake of fire and Satan being cast and bound in a pit. It also completes with the final demise of the wicked known as the grapes of wrath in the winepress of God.
The last battle of all time, will happen after the Millennium.
A special time of Millennial reign of Christ on a redeemed earth will follow. After this 1000 year time period, Satan will be loosed for one last time. This will close with one last battle of all time; ending with Satan losing again and being cast into the lake of fire, for ever. Hallelujah, Amen.
BATTLE 1 - AT THE END OF THE 7 YEARS OF THIS AGE - ARMAGEDDON
Revelation 19:11-15 Now I saw heaven opened, and behold, a white horse. And He who sat on him was called Faithful and True, and in righteousness He judges and makes war. His eyes were like a flame of fire, and on His head were many crowns. He had a name written that no one knew except Himself. He was clothed with a robe dipped in blood, and His name is called The Word of God. And the armies in heaven, clothed in fine linen, white and clean, followed Him on white horses. Now out of His mouth goes a sharp sword, that with it He should strike the nations. And He Himself will rule them with a rod of iron. He Himself treads the wine-press of the fierceness and wrath of Almighty God.
Revelation 19:19-21And I saw the beast, the kings of the earth, and their armies, gathered together to make war against Him who sat on the horse and against His army. Then the beast was captured, and with him the false prophet who worked signs in his presence, by which he deceived those who received the mark of the beast and those who worshiped his image. These two were cast alive into the lake of fire burning with brimstone. And the rest were killed with the sword which proceeded from the mouth of Him who sat on the horse. And all the birds were filled with their flesh.
So this battle is at the end of the last seven years of this age; the beast and the false prophet are cast alive into the lake of fire and Satan is bound in the bottomless pit for a 1000 years. Note: the beast and false prophet meet their demise at this time, not at the rapture.
Revelation 20:1-3 Then I saw an angel coming down from heaven, having the key to the bottomless pit and a great chain in his hand. He laid hold of the dragon, that serpent of old, who is the Devil and Satan, and bound him for a thousand years; and he cast him into the bottomless pit, and shut him up, and set a seal on him, so that he should deceive the nations no more till the thousand years were finished. But after these things he must be released for a little while.
BATTLE 2 - AFTER THE 1000 YEARS - THE FINAL BATTLE
There are 1000 years set aside by God since the beginning. In a way, it is a Sabbath millennium, following 6000 years of God working with mankind. This will be a millennium of peace and no devil or demons running about the earth. It will be similar to the Garden of Eden, but with no devil popping in until its completion.
After the 1000 years of peace have passed, Satan will be turned loose so that those who lived and were born during this time, can be tried and tested. No one gets to heaven permanently without two things: One, Jesus is the only way in and two, all have to be tested. This is just the way it is. And after Satan is loosed and done his bidding, he will make his last effort of all time, to attempt to usurp God once more.
Revelation 20:7-10 Now when the thousand years have expired, Satan will be released from his prison and will go out to deceive the nations which are in the four corners of the earth, Gog and Magog, to gather them together to battle, whose number is as the sand of the sea. They went upon the breadth of the earth and surrounded the camp of the saints and the beloved city. And fire came down from God out of heaven and devoured them. The devil, who deceived them, was cast into the lake of fire and brimstone, where the beast and the false prophet are. And they will be tormented day and night forever and ever.
Satan will be thrown into the lake of fire and brimstone for the rest of eternity. He will join the beast and false prophet who will already be there.
Also happening at this time, will be the Great White Throne of Judgment (Revelation 20:11-15) and the departure of the old heavens (the physical ones, our solar system, etc. - not the place of God's throne and the saints) and old earth by fire (2 Peter 3:10-12).
And Father God will have what He longed for in His heart.
Revelation 21:1-3 Now I saw a new heaven and a new earth, for the first heaven and the first earth had passed away. Also there was no more sea. Then I, John, saw the holy city, New Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband. And I heard a loud voice from heaven saying, "Behold, the tabernacle of God is with men, and He will dwell with them, and they shall be His people. God Himself will be with them and be their God."
But you, brethren, are not in darkness, so that this Day should overtake you as a thief. You are all sons of light and sons of the day. We are not of the night nor of darkness. Therefore let us not sleep, as others do, but let us watch and be sober. 1 Thessalonians 5:4-6
While we do believe in a mid tribulation rapture, we are not saying we know the day or the hour. The Lord makes it very clear that no one but the Father knows that. While we do believe it is at or near the middle of the last 7 years of this age, the Lord says that He has to cut the time short for the elect's sake in Matthew 24:22 and who knows the amount of time that will be?