To me, good manners are esential for telling/showing someone they are important. It's a way we show 'preference' in that we show/let someone know that they are importnt to us, maybe even more important than our own wants and desires.
To some, I live in the land of good manners- England. I agree that English writers have produced a number of good books on the subject and many of the Queen's subjects display great qualities of consideration for others, but the English version of manners is only one version of the etiquette we have agreed to call "manners."
Each culture has a group of behaviours and words considered to be "best manners." Best manners are often about protocol, and I prefer to think more in terms of "simple manners." It's not complicated to say "sorry, love." when we have hurt someone with words or behviours even if we have no idea what we have done. It isn't pretentious to apologize and save sorting out the resons behind a hurt for a later date.
It is pride that keeps us from acknowledging our humanness and our willingnes to "prefer one another." Pride keeps a wife from apologising for dinner not happening, a nation from the starting point of reconciliation with another nation, and me laying my whole life at the foot of the coss.
On this Holy Weekend I want to say sorry to God in the name of Jesus...not a light or polite or flipant "sorry" but a more deeply felt "sorry" that my countries where I have a passport, where I live and play are not raising the name of Jesus above all other names. May nation upon nation prefer you.