Throughout the poem, "Sir Gawain and the Green Knight," Sir Gawain encounters numerous trials testing his religious faith and his devotion to Christianity. When Gawain go forth on his journey to find the Green Chapel, he discovers that he has become lost; it is only after praying to the Virgin Mary that he finds his way. As he, then, continues, Gawain suffers from anguish that he must inevitably encounter the Green Knight. However, rather than praying to Mary as he has done before, Sir Gawain decides to use the girdle given to him by Bertilak's wife.
From the Christian perspective, Gawain has fallen from grace. After he suffers the consequences of his lack of faith, Gawain is forced to reevaluate his faith when the Green Knight points out his betrayal. Gawain's rejection of assistance from the Virgin Mary indicates his human fraility and his sin.
In addition, when Sir Gawain sets out upon his quest for the Green Knight he has a shield that has a pentagon on the outside and the picture of Mary on the inside. The five points of the pentagon represent a set of his virtues, his five senses, his fidelity founded upon the five wounds of Christ; and his force, founded on the five joys of Mary, and the five knightly virtues.
As the fair maid inspires the knights to courtly love and chivalrous deeds, Mary inspires Gawain to be a good Christian.