Sometimes its fun to get into an argument over religious or political topics and leave it at that. I have no illusions that my arguments are going to change someone's mind when we are at opposite ends of the spectrum. But sometimes its a fun challenge and in those cases, it should be no-holds-barred. If everyone understands the context and that it isn't personal, it can be a great learning experience.

Most other times, I don't feel like getting into it with someone and just want to goof off and have fun with no thought of the differences I have with the people I am around. In those cases I don't want to discuss the "hard topics."

I think friendship starts when two people can have it out with each other but be mature enough to let it go when it is finished and be able to enjoy each other's company in a casual context.