This is the central conflict which Gawain must deal with in his quest. He is forced to confront the forces of Nature both external and internal -- in the form of the Green Knight, the winter landscape, his own sexual desire, and ultimately, his own fear of death. Throughout, Gawain counters this with his own faith in God and in chivalric values. But in the end his natural fear of death overcomes his sense of human morality, causing him to accept the green girdle. And when Gawain returns to human society at the end of the poem, it is with a sense of unease, having realized the power of Nature in comparison to his human beliefs. Throughout the poem, we see natural settings and impulses constantly opposed to those of human society and civility. And while humans shy away from their inevitable death, it is Nature which can continue to restore and regenerate itself, as seen in the indestructible Green Knight and the passing and resurrection of the year.
