You can see the distinction, surely? Islam creates space and justification for these actions in a way that Buddhism, Hinduism and Christianity does not. It's a difficult to swallow pill yet it's true.
Source: Am an ex-muslim and generally interested in this phenomenon.
But my point is the current terrorist attacks in Paris are committed by people who got discarded by society with no purpose in life and they found a group who gave them a place where they felt needed and respected.
Brevik is a Nazi and he is not Christian
Some books are much better at this than others. And while I don't believe the bible was that prevalent in the wars of the past, even if it was, that was centuries ago. We've cast aside such foolish things yet live in a world where many people have not.
And that's our problem.
On your second paragraph - that's exactly why an ideology that can transform a person from a citizen into a terrorist because they feel marginalized needs to be addressed. There's a whole lot of marginalized people across our globe.
While it's true that many disfranchised individuals turn extremist it's also true that just as many of those who do are very privileged. People don't decide to join ISIS because they are poor, the do so because they are influenced to do it in a very methodical and well financed way.
Credit to you; that's not an easy (or particularly safe) path to walk.
https://www.google.com/trends/explore#q=islam%2C%20terror%2C...
Draw your own conclusion.
Plus I don't think you really want to make this association. Breivik was a (neo-)Nazi (e.g. [1]). If anything he supports the argument that ideology leads to terrorism (it is baffling to me that anyone would ever think it doesn't). I don't think anyone is making the argument that there is only a single violent ideology on this planet.
But I find it weird that to make your point you'd draw attention to the association between terror and ideologies. Because then you'd very quickly arrive at the obvious question : per ideology, how much terror, and at what point do we take action ? Per ideology, how much terror is something the above graph can help with.
[1] http://www.independent.co.uk/news/world/europe/anders-breivi...
Religion has no part in this its only a vehicle as is Christianity. The real picture is much bigger and more complex.
And please look behind the media curtain as other have pointed out you have the internet on your hands you can get all the sources you need.