Life is not a debate. We don't have to hold the line in a conversation because we have to prove point. We do not have to show that the other person is wrong, at the expense of conversation and the price of verbal conflict. Sometimes we should just let a point go.
Letting go is especially difficult when it comes to personal opinions. While it is true that all viewpoints are moot, that doesn't mean that we have to show the other person that their perspective is flawed. It's only flawed because we hold an opposing view. Learning to respect another viewpoint, and accepting that everyone is entitled to their own, is the first step toward better relationships with others.
Sometimes others are simply wrong. We don't have to prove them wrong. Yes, it may be a serious matter and they may be better off knowing that they are wrong and correcting their actions. However, don't try to force them to drink. If they adamantly refuse to see reason, there is no point in engaging in debate. You either get it, or you don't.
Finally, we should always consider the possibility that we are wrong.