It is very common to notice two people not sharing the same opinion on any topic, situation or solution to a problem. It is natural. Everyone has their own perspective and their own life experiences and their own learnings which results in the difference of thoughts and opinion.
If this is so clear then why do people fight and argue with each other?
I have experienced almost every relationship whether it is being a daughter, sister, friend to few, colleague to many, employee, wife, daughter-in-law, sister-in-law, and now a Mother. Any relationship is never always the same. Sometimes it brings happiness and peace while other times it is cause for misery and tension.
My experience says that as long as people share the same opinion any relationship is harmonious. But the problem comes in when there is a difference in views. Managing differences in opinions and views is a challenge for sure. What is even more challenging is to maintain the dignity and respect of the relationship while expressing our views.
It is easy to prove oneself right and others wrong but what is difficult is to accept that you are wrong and the other person is right. And even more difficult is to apologize for the wrong.
Wise people tend to manage it successfully.