TigerTimwhy is the debate of religion so problematic in the first place? And what steps can we take to ensure that if we choose to participate in the debate that we are not misunderstood and that we do not give offence?
I can only speak from my own experience. One thing is that religion is a very personal matter that people feel very strongly about. Even those that eschew religion are extremely passionate in their beliefs.
Another thing to consider is that some people are uncomfortable with the subject altogether, and become offended at even the mention of religion.
Then there's the matter of one person explaining how and what they believe to another. Even when the intent is to have an amicable discussion, it's all too easy for one person to mistake another's passion in their belief for prostelytizing.
When you're dealing with an open forum or a large group of people, you also often run into somebody popping in with the intention of starting a flame war, and those persons will, undoubtedly, say something rude or disparaging about someone's beliefs... and you get an instant war.
In a discussion of religion (or politics), it is important to carefully choose your words so that you remain clearly understood (though most people lack such a level of vocabulary when expressing religious beliefs), to have respect for the beliefs and opinions of others... even if you disagree or think it silly, and to avoid attacking or belittling the beliefs of the other person. Attitudes have to be checked at the door, or the whole discussion will devolve into a fight.
For example: In a discussion of religion, if someone states what they believe, the wrong thing to do would be to follow with a comment such as "good thing I'm not superstitious"... because the first person is going to assume you're writing their beliefs off as mere superstition and they're going to get pissed. Result: Instant flame war... unless one of the two parties has the vocabulary to nip it in the bud immediately.