The Battle of Armeggedon will be so one-sided that it can scarcely be called a battle. The fleshly armies, the humans gathered to gather from all over Earth against God and against the Jewish people, we be easily destroyed by Jesus. There will be no prisoners in the conventional sense:
Then I saw the beast and the kings of the earth and their armies gathered together to wage war against the rider on the horse and his army. 20 But the beast was captured, and with it the false prophet who had performed the signs on its behalf. With these signs he had deluded those who had received the mark of the beast and worshiped its image. The two of them were thrown alive into the fiery lake of burning sulfur. 21 The rest were killed with the sword coming out of the mouth of the rider on the horse, and all the birds gorged themselves on their flesh. (Revelation 19:19-21)
The result of this battle will be the complete annihilation of the humans who follow the false prophet and the beast. Everyone will be killed painfully (see Zechariah 14:12). The two greatest trouble makers, the false prophet and the Antichrist, will be cast immediately into the Lake of Fire. This is the eternal abode of those who reject God. The rest of the dead will be sent to hell, a temporary holding place of great suffering which will later be emptied into the Lake of Fire (Revelation 20:14). The false prophet and the Antichrist will have to experience the lake of Fire longer than anyone else, as a punishment for their lead role in deceiving the people of this world.
Modern audiences do not like to read about all this doom and gloom that I have described above. This is the part of the Christian religion that many people would prefer to delete out of our Bibles, because it describes a God of vengeance whom they do not like. But this God of vengeance is also a God of love. He has granted our planet mercy for at least two thousand years, holding off Christ’s second coming and the corresponding judgment so that more people would have time to repent.
His judgement must come, but His loves comes first. Jesus first coming was about love and sacrifice for sinners. Jesus’ second coming will be to reap justice on those who have oppressed others and not repented.