World War I, religion died in the 20th century, science triumphed in religion in the

[Belacqua]

the Crimean war in the 19th century was based on the struggle of Catholics and Orthodox for some kind of church in some kind of Jewish city

Well, kind of.

The protection of religious rights was the immediate cause. But religious rights are easily ignored if there's no power at stake. The war wouldn't have happened if the Ottoman Empire weren't collapsing and Western European powers hated the idea of Russia gaining territory. 

But, OK. Let's pretend the Crimean War was about religion. Does this mean that WWI was the first not to be religiously based? Because I think you're not going to be able to support that.