go out more and try and have arguments with people. It's scary stuff to face the prospect of getting beaten to a pulp. The internet is so much more comfortable knowing full well you can disagree with some one and face no physical harm.
The definition of "internet tough guy".
Just because I start an argument does not mean I rage. I can indeed work myself up, but that only happens when people are being exceptionally dull. Just because I swear does not mean I am raging. I debate with people because it is an intellectual exercise that helps me think about things in a broader sense.
This isn't about just you, it's about everyone who wages the war. You may be calm in your debates at some times, but other people aren't, and just go batstuff.
I guess if it was possible to have an intelligent discussion about religion, it wouldn't be so bad, but from what I've seen it always ends up with people slandering the other person's beliefs.