Lessons from Epictetus

22. Appropriate acts are in general measured by the relations they are concerned with. “He is your father.” This means you are called on to take care of him, give way to him in all things, bear with him if he reviles or strikes you.
“But he is a bad father.”
Well, have you any natural claim to a good father? No, only to a father.
“My brother wrongs me.”
Be careful then to maintain the relation you hold to him, and do not consider what he does, but what you must do if your purpose is to keep in accord with nature. For no one shall harm you, without your consent; you will only be harmed, when you think you are harmed. You will only discover what is proper to expect from neighbor, citizen, or magistrate, if you get into the habit of looking at the relations implied by each. (Epictetus "The Handbook")

Epictetus teaches a big lesson about family here in this passage from The Handbook. He teaches that according to nature, you are only guaranteed to have a father or mother. It is not guaranteed that you will have a good father or mother, or even a bad one. Just that you have been given a father or mother, naturally. This means that no matter how they are, they are your father or mother, and so you must treat them as such.

He also goes on to say retain your relation with him (or her) and don't think of if they are bad or good in your own standards, but instead accept that they are your parent according to nature.

This part is important in all aspects of life, family or not: For no one shall harm you, without your consent; you will only be harmed, when you think you are harmed. The only way you can be harmed, emotionally or mentally, is if you allow yourself to be harmed. Raging and being angry are actions that you allow yourself. Nature shouldn't make you upset because it has given you a bad father or mother. You are allowing yourself to dwell on the fact that you have a bad father or mother, and not accepting what nature has accorded you. The only person who can hurt you is yourself.

We have such short lives, so little time together, that to dwell and fester on the simplest things can just be a waste of time. So allow yourself to not become consumed by rage only caused by yourself and begin to enjoy your life for what nature has given you.