I would say this is true in the vast majority of cases, except where the parties involved are intellectually honest enough to really consider different views. I myself have contributed to other people changing their religious views, and my own personal views on things have drastically changed thanks to discussions with other people.

However, the key thing is that it's not something you can really aim for. If you're in a conversation where both sides are sincere, each sides will eventually learn something from the other and it may or may not happen to be religious or political or something else. But if you go up to a distant coworker, stranger, or someone like that, you're just going to be a bunch of statements that they reject from the get go. So aside from those few exceptions, you're right, people will just disagree and aren't really open to considering different beliefs.