13-18

13.) Line 102-109 ~ Grendel was the name of this grim demon haunting the marches, marauding round the heath...Cain got no good from committing that murder
        

Grendel is from Cain's Clan. Cain killed his brother Abel, because he was jealous and God cast him into exile. From Cain's anger and sadness came Grendel and other monsters. Like Cain Grendel can't be helped by other men because of the mark placed on him by god, so he lives as an outcast. 

14.) Lines 799-802 ~ When they joined the struggle there was something they could not have know at the time, that no blade on earth, no blacksmith’s art could ever damage their demon opponent.

Grendel has been cursed with the mark of Cain. The manmade weapons don’t work on the curse. This may be a foreshadow to Beowulf not being able to use Unferth’s sword on Grendel’s mother. The sword he used to cut her head off was made by the giants.

15.) Lines 2802-2808  Order my troop to construct a barrow…as they steer ships across the wide and shrouded waters.

Beowulf’s final instructions. He orders his troop to build him a barrow by the sea so he will always be remembered. He may have told him to put it on the coast not only to travelers will see it and remember him, but to try and ward off any kings looking to take of Geatland. Seeing the barrow would remind them that Beowulf was a fierce warrior and may have trained others to be as great as he.

16.) Lines 2401-2407 ~The Lord of the Geats took eleven comrades… and was now added as a thirteenth to their number.

One leader, Beowulf, and twelve followers alludes Jesus and his twelve disciples.

17.) Lines 2510-2515  Beowulf spoke, made a formal boast for the last time…if the evil one will only abandon his earth-fort and face me in the open.

Beowulf’s final boast. He understands that he is old and probably won’t live through this battle. He is putting everything on the line and leaving everything up to fate. He will go into the battle with the will to win, he won’t stop fighting until the dragon is dead.

18.) Lines 2207-2211 …the wide kingdom reverted to Beowulf. He ruled it well for fifty winters, grew old and wise as warden of the land until one began to dominate the dark…

This is a parallel to Hrothgar’s life in Heorot. Hrothgar also ruled for fifty years until a monster (Grendel) wreaked havoc among his nation. The same is happening to Beowulf.