There will be millions of people engaged in the Battle of Armageddon, as all the nations gather together to fight against Christ.
The exact location of the valley of Armageddon is unclear because there is no mountain called “Meggido.” However, since Har can also mean “hill,” the most likely location is the hill country surrounding the Plain of Meggido, some sixty miles north of Jerusalem. More than two hundred battles have been fought in that region.
The Plain of Megiddo and the nearby Plain of Esdraelon will be the focal point for the Battle of Armageddon, which will rage the entire length of Israel as far south as the Edomite city of Bozrah (Isaiah 63:1).
The valley of Armageddon was famous for two great victories in Israel’s history:
Barak’s victory over the Canaanites (Judges 4:15) and Gideon’s victory over the Midianites (Judges chapter 7). Armageddon was also the site for two great tragedies: the death of Saul and his sons (1 Samuel 31:8) and the death of King Josiah (2 Kings 23:29-30; 2 Chronicles 35:22).
Because of this history, the valley of Armageddon became a symbol of the final conflict between God and the forces of evil.
The word Armageddon only occurs in Revelation 16:16,
“Then they gathered the kings together to the place that in Hebrew is called Armageddon.”
This speaks of the kings who are loyal to the Antichrist gathering together for a final assault on Israel. At Armageddon “the cup of the wine of the fierceness of God’s wrath” (Revelation 16:19) will be delivered, and the Antichrist and his followers will be overthrown and defeated.
Armageddon has become a general term that refers to the end of the world, not exclusively the battle that takes place in the Plain of Megiddo.
Original Source: gotquestions.org