There was supposed to have been a significant war at the plain of Megiddo. For the locals it became a byword for a decisive war. Later religiously minded writers used the war at Megiddo as a picture of final conflict between good and evil. This was purely a religious vision not based in fact or reason.
Not a million miles away (2450 miles actually!) from Megiddo in Northern India sits another battlefield in a region called Kurukshetra, the site of the greatest battle in the Mahabharata. To Hindus this much older epic war carries the same meaning as Armageddon did to the inhabitants of Canaan-- but stories are not prophetic and there is no reason to believe in a big showdown between good and evil.
The whole belief thing is rooted in imagination and human yearnings for something better..