Beowulf is a story of heroes, monsters, battles, and death. All four of these things play a role in the theme of this story, the theme of good versus evil. The theme of good versus evil is evident in the story but one is the victor over the other. Good prevails over evil in Beowulf, and it is evident in the fights between Beowulf and Grendel, Grendel's mother, and the dragon. .
Before a person can see that good prevails over evil, they must see what is evil and what is good. The first monster ,Grendel, is characterized as an infernal creature, a fiend of hell, "hell's captive", an alien spirit, a companion of "devils", and indeed a devil himself (Parks 4). He was a powerful monster, living down in the darkness/ Growled in pain, impatient (lines 1-2). Beowulf comes as a God sent deliver to cleanse Herot (Goldsmith 85). Beowulf represents the good while Grendel represents the evil. Beowulf is here to save the people of Herot while Grendel is here to terrorize them. .
In the story, while Grendel's man-eating habits dehumanize him, he exhibits human life habits and may have mastered certain human arts (Parks 4). This suggests that that while Grendel goes to Herot eating and killing men, it is not because he is an obtuse monster, but that he is an intelligent monster who is fully aware of his actions. Grendel wants to ravage like a predator, whereas Beowulf insists on contesting with him like a conspecific adversary (Parks 4-5). Grendel is evil because he wants to be and Beowulf knows that. For Grendel, nothing quenches his lust for evil. In battle Beowulf defeated Grendel, which is an example of good prevailing over evil. .
The next fight is between Beowulf and Mother Grendel. In keeping with the habits of her clan, she too introduces herself to the Danes predatorily (Parks 5). In the speech to Beowulf the next morning Hrothgar characterizes her assault as an act of vengeance within a feud (Parks 6).
