In a family, the two most important things you can, and have to, say is “I love you” and “I’m sorry”. Unlike the screenwriters’ opinion that “Love means never having to say you’re sorry”, in my opinion love means having to say it more.
Your family is closely connected to who you are and why you are; so much so, they become an extension of your being. And as a human, sometimes you tend to be as hard on them as you are on yourself.
People expose their emotions, their weakness, and their dreams to family that they don’t to the “outside world”. In stressful and/or weak moments, this information can become ammo in an internalized situation.
Just a few weeks ago my sister and I got in an argument. Her and I hardly ever argue and we both found ourselves saying hurtful things. But, they weren’t really meant at the other person. They were just misguided communication tactics to try and express the internal hurt and fear we were feeling.
The important thing we did after we both calmed down was talk it through and take that step in understanding the other person’s emotions and fears. Our friendship, our love, and our respect for each other overcame the negative and hurtful things we said.
Like I always say, “Family is forever and God wouldn’t have put you together in life if you couldn’t handle it.”
Here's the article from Beliefnet GLOW. It's very interestingand takes a unique perspective on apologies. How to Say 'Sorry'