Analysis short story on “To Hell With Dying” Alice walker

What are the three characteristics of fixed poetry

In this excerpt from "dover beach" by matthew arnold, which two lines or sets of lines suggest that the speaker has undergone a loss of faith? the sea of faith was once, too, at the full, and round earth's shore lay like the folds of a bright girdle furled. but now i only hear its melancholy, long, withdrawing roar, retreating, to the breath of the night-wind, down the vast edges drear and naked shingles of the world. ah, love, let us be true to one another! for the world, which seems to lie before us like a land of dreams, so various, so beautiful, so new, hath really neither joy, nor love, nor light, nor certitude, nor peace, nor for pain; and we are here as on a darkling plain swept with confused alarms of struggle and flight, where ignorant armies clash by night.

The knights of the round table were bound by the code of chivalry that called for loyalty to king, god, and lady.  in which set of lines from  sir gawain and the green knight  does sir gawain describe upholding this code?