Eh. That's not JUST religion. I just learned about the Rose War in Social Studies a few days ago. A guy with a crest of a white rose was in a war with a guy whose family crest was a red rose. My teacher quoted it as "The only war where men would die over the color of a rose without knowing what it stood for." (Incidentally, this war was the basis of the majority of the storyline in FFT; The "Lion War" between Larg and Goltana because both of their family crests had different colored lions on them, for instance, and the way that King Richard III was king because he was the regent over the true rulers until they were eighteen, much like Larg had regency over two-year-old Prince Orinas.) Basically, people will die for whatever they're taught. Most people use religion as a basis of their life - when that is threatened, they'll die for it.
Are you all telling me you wouldn't take a bullet to save an FF game?