Many religious people often ask the question as to why we argue with them. "Why bother?" "Why spend so much time arguing/debating with someone for whom you disagree?" "Isn't it just a waste of time?" "You're not going to change anybody." "Why are you trying to tear down the beliefs of others instead of focusing on your own beliefs?" I wanted to respond to this and perhaps some of you might feel compelled to chime in.
First, there is a distinction between what most people call "arguing" and what I call debating. Rational interchange (even if sometimes passionate) is not the same as arguing (i.e. - verbally fighting) even though they sometimes can look similar to some people. For those religious folks who may be reading this, please understand that it is not our intention to "argue" (most of the time) but to debate, and that most often requires rational "sparring" (which of course requires the use of logic, reason, and evidence). Since the best and virtually only reliable method for separating fact from fiction has been demonstrated as the use of logic, reason, and evidence - and since most of us atheists care about whether or not our beliefs are actually true - it makes sense that we want to debate/argue. In short, we care about truth and that sometimes requires an exchanging of disagreeing concepts in the marketplace of ideas. So don't get all bent out of shape when we want to debate with you. We like it. It's challenging, educational, and fun. And since many of us value education and higher learning we enjoy the activity of debate.
Now, why do I decide to engage you Christians, Muslims, and Jews in debate regarding your religious beliefs? In short, because beliefs have consequences. No one holds their beliefs in a vacuum. Your beliefs effect countless influential decisions you will make; including (but not limited to), who you will vote for (both locally and nationally), what rights you will fight to protect (and what rights you won't defend), what science you will support or oppose, what companies you will support or work for, where you will put your money and how you will use it, how you will treat children, how you will respond to criticism, what justifications you will make for your deeds, and so on and so forth.
So then the main reason I debate with you theists is because your beliefs effect me (both directly and indirectly - and especially when it comes to law, policy, education, and personal rights). Due to the fact that I strongly disagree with most religious belief (it is in fact superstition etc) I would like to see those views either modified or overturned. So there, now you know my motives and intentions when I debate with you on these forums and the question no longer needs to be asked.
p.s. - To those who think, "You're never going to change anyone" I say BULLOCKS! I changed my mind (about Christianity and the bible) as a direct result of debating online and with ex-Christian friends, who I am now very grateful to have in my life. Change DOES happen, all the time.