Mention of 'hell'?
Presumably the majority of people (Swedes and Danes) in this 5th century legend, set in pre-Christian Denmark, are not Christians? The modern English word 'Hell' is derived from Old English helle (about 725 AD to refer to a nether world of the dead), Old Norse hel.
After Beowulf killed Grendel, King Hrothgar, Beowulf and his surviving men give the honoured dead a warrior's fire funeral. It is then that Beowulf mentions the 'foul beast from hell'?
Hell, the Christian antithesis, is surely a word that would not have been uttered by pagans?
Even the 'older' Beowulf mentions Jesus/God as the "Christ God" in a distant way?
I could be wrong but it seemed as odd as Maximus's Roman saying it in Gladiator?