For God and Country
You're right about most religious wars being really wars about resources and markets, maybe our Bronze and Iron Age ancestors were more honest about it and didn't make up excuses. They also talked about conquest, manifest destiny, personal honor and glory. But I think it still holds that the religious excuse wasn't used until the Christians and Muslims started talking Jihad and Crusade in the middle ages. Of course, that didn't stop either of them from waging war on their own co-religionists for the traditional reasons.