Have a viewpoint. Stand for something. If you don’t, you stand for nothing at all.
We don’t have to agree with others all of the time. But when you don’t, be respectful. Agree to disagree. You learn more from dialogue with someone you don’t agree with than with someone you agree with.
Plus, none of us are right all of the time. If someone says something that makes you potentially rethink a position or opinion, take the time to think about it or research the matter. Always try to speak from a position of knowledge, i.e. if you don’t know about a particular topic, don’t speak like you do. Those who do will know you are full of hot air and it will harm your reputation.
So don’t have a slinky for a spine. And know to keep quiet on topics you don’t know about. It will allow the backbone you should have not to be snapped, along with your reputation.