Yeah, that's true. Religion or religious beliefs have been the reason or a contribution to several aggressions in history and now. Unless you're a pantheist, or inclusivist/pluralist religion. That way there's nothing wrong!!1 I mean, I haven't ever heard of a single problem with Bahai aggression, though apparently Buddhist terrorists exist. Which is rather confusing. I don't really understand how that works.

I don't have, and haven't looked for, a source on that subject. That's why I said 'apparently'. If I find one I'll edit this and add it in. Otherwise, assume that I was misinformed and blargleblarg. :3

EDIT
Okay, apparently they do exist. And in quite a few numbers. The Aum Shinrikyo was based upon Buddhist teachings. Through history there have been numerous Buddhist warriors who 'purged' the land of certain factions. Lots of stuff. There's even actual teachings of violence by Buddhist doctrine, according to the Wikipedia page.

• Buddhism and violence
• War in Buddhist history

There's probably more specific articles available, but Wikipedia tends to have them all in a big compendium. And Wikipedia makes you automatically right in debates because that's how debating works. Cite Wikipedia. Get money. :D