The ethos of Sir Gawain and the Green Knight is principally Christian, and the culture of Christianity permeates the narrative. The Green Knight offers his challenge to Arthur, then to Gawain, with reference to his Green Chapel, and that is a referent unique to Christian culture. The referents multiply. When Gawain is searching for the Chapel, he continually asks strangers to point him in the direction of shelter where he may "pray my Paternoster, Ave, and Credo," and he prays that "the Cross of Christ speed me" in his quest (Weston). He asks for food and shelter in the name of God and Christ and Mary and prays to them that he may have shelter to praise them. Faith guides his path and his very being. Small wonder the medieval period was called the "age of belief" (Fremantle passim).
Yet the entire action of the narrative has a pagan origin, as the narrative makes clear, and it is the pagan intent to subvert Christian constancy. As it turns out, Morgain le Fay--nemesis of Arthur and Camelot entire--has engineered the entire process. Much against Morgain le Fay's wishes--Gawain proves himself a constant fellow, not only because he has absorbed the lessons of Christian doctrine but also because he embodies the ethos and values of the chivalric code associated with the Round Table. As Gawain explains when the Green Knight offers his first peculiar challenge: "Gawain am I, who give thee this buffet, let what may come of it; and at this time twelvemonth will I take another at thine hand with whatsoever weapon thou wilt, and none other" (Weston).
In this text, only chivalric honor and Christian constancy can match the challenges of paganism. In that regard, Morgain le Fay is described as a goddess, having been mistress of Merlin and having experienced betrayal by Arthur, whom she had apparently hoped to conquer once for all. The whole matter of the Green Knight was Morgain le Fay's stratagem; she wanted the spectacle of the headless gre...