I would probably have to go with religion, though politics, sex (largely due to religion) and sports get pretty tense.
Link, I find it curious that you state that a topic can’t be debated because it’s based on faith, not facts. Much of science is based on faith. What evidence do we have for the Big Bang? Yet it is discussed in scientific circles as having legitimacy. There is no evidence for that and many other “facts”, yet they are debated. Weren’t medical procedures of the 1700s accepted as ‘fact”, that are now clearly regarded as without scientific basis? Wasn’t it accepted as “fact” that some people were witches and had magic powers? I could go on and on. It’s all perspective, and in my opinion, scientists are the WORST examples of having faith. They believe something, so they go look for evidence to support their beliefs. I can tell you with CERTAINTY, though there is no physical equipment to define, measure, or show it’s physical existence, my faith in Universal Energy is rock solid and I am open to information, not necessarily evidence, that appears logical in the full context of life. I don’t need something to measure it in some small and specific instance to prove it’s existence.
To me, faith in anything is simply an inherent awareness by some people for which we do not yet have the technological awareness to understand and quantify it. I think you should have a more open mind.
I think religion is most contentious thing to argue. People are totally involved in their religion which is really just a figment of their imagination. Religion is a real circular logic Catch-22. You can’t escape believing or not believing. either way, the boogie man is going to get you. It’s all a bunch of BS.