Beowulf says in the text that "Fate goes ever as fate must." This shows how Anglo-Saxon society highly valued fate and its mysterious ways. He knows that he might defeat Grendel, but he also knows that the reverse might happen. Beowulf is aware of the fact that not his deeds, but fate decides what is going to happen in the future. Based solely on the will of fate, Beowulf defeated Grendel, and fate decided that in the end Beowulf will be defeated by the dragon. It all depends on fate, and Anglo-Saxon people knew that.
