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.
I could almost see that happening to you. You're somewhat forceful in real life, and from what I've seen you don't really let other people explain themselves.
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.
I usually just try to disprove or prove what people say based on what I've learned. So, if they say something about evolution, and it's wrong, I explain why and give them a chance to further explain their original statement (sometimes people just forget to say one thing and it just ruins their whole argument).
I usually don't post about religious statements since I cannot very easily disprove them. I have been taught more about evolution and scientific beliefs than I have about biblical stories.