I'm always aware of that. Religion is one of the most prominent facets of people's lives. Some tend to take it as a personal attack if you even start asking questions that go against what they believe.
When it comes to debates on forums here I'd also recommend looking through the posts of anyone you're currently arguing with if it's a long thread. You may be able to learn more about their psychological state and think process and biases. You may even discover some contradictions you can expose.