Why is it significant that Grendel is "kin of Cain?"

Question

I need to know this answer to this question for my beowulf assignment 

Answer 1

From the Internet:

 

Cain, in the Bible (Hebrew Bible, or Old Testament), firstborn son of Adam and Eve, who murdered his brother Abel (Genesis 4:1–16). Cain, a farmer, became enraged when the Lord accepted the offering of his brother Abel, a shepherd, in preference to his own.

 

 

People who are kin of Cain act like Cain.  They are jealous, want revenge, and may even commit murder.