Knowing what a symbol is, what might Beowulf and Grendel symbolize?

Beowulf is clearly an Anglo-Saxon hero who accepts that his fate (Wyrd) is to fight against the evil that Grendel symbolized. The original scop who told this tale undoubtedly would have seen Beowulf as good and Grendel as evil. They would have symbolized the two forces that seem most contrary in the world as they saw the world.

Beowulf symbolizes heroism and a code of honor. Grendel symbolizes a presence viewed as alien or sub-human.