Keeping yourself open to change is important. Allowing yourself to see other peoples opinions is important. It doesn't mean you have to agree, but it doesn't mean you have to disclose your disagreement unkindly.
Speak with truth, if your wrong admit your wrong - being wrong helps you grow. If your right, know your right - but don't throw someone's wrong doings in there face. Being gentle. We are all in different places and spaces in our life. You never know what someone else is gong through underneath the exterior.