Most believers (in our finer moments) desire sanctification. We long for more holiness to be exhibited in our lives, but we feel at a loss for how to get more. Well, if we just open our eyes, we find that the Lord GAVE us an avenue to acquire more of it right in our own homes. But most of us have shunned any help coming from THERE, either overtly or subtly. We have to look no further than our own homes to go to get it because our heavenly Father built into the home the best mirror that we shall ever have.
If anyone in your family tells you even the slightest thing that irritates you, LISTEN and go to work on that area. The comment might come from a young child, an extended relative, a spouse. And re-examine the purpose of manners and seek to increase your expression of them. Manners elevated us above savages – they took centuries to develop and we note when a person has them and when a person doesn't.
Just ask yourself, when a family member says something is bothering them, what is our usual response? We don't naturally retreat from that behavior. Instead, we EXPLAIN WHY we did something. We entrench, and we think nothing of doing it again. If we would, instead, become responsive to such comments, we would grow in grace.