Take manners, for example. Manners can be described as love in trifles, love at the periphery. The collapse of manners in our society — a peripheral thing, surely! — represents a true downgrade. But here is Chesterton: “Love of humanity is the commonest and most natural of the feelings of a fresh nature, and almost everyone has felt it alight capriciously upon him when looking at a crowded park or on a room full of dancers.” Those activities are out at the edges, but by looking at the edges we can see the centre. You give the last piece of pie to God, who doesn’t eat pie, by giving it to your neighbour, who does. That is the point of courtesy, manners, etiquette — consider 1 Pet. 2:17; 3:7; 1 Tim. 5:17; 6:1; Eph. 6:2; Rom. 12:10; 13:7.
For more examples and some lucid thinking on this important subject, read the rest of Doug's post here