the only war that is a real religious war is whats happening right now with islam in the middle east.every other war in history had other factors involved which were not religious.world war 1 and 2 were not started and fought because of a religious conflict.please study history some more and dont except the bullshit idea of history that was spoon fed to you by the education system of america
Generally when one refers to religious wars they're usually harkening back a bit further then WW I or II. It's typically a reference to the Holy Crusades and the Spanish Inquisition, two times in Christian history when unspeakable torture was inflicted on anyone not getting on board with how the ruling class saw things.