There are many biblical references in Beowulf stick out like a shore thumb. Besides the use of the biblical figure of Cain being used to compare him to Grendel, there are many others. Some of which are the more notable ones is the mentioning of the worldwide flood and the Christian idea of sharing treasure, giving away rings. These references are also there to prove a point to the intended audience of the time.
The biblical use of the flood is made clear when King Hrothgar peaks of the worldwide flood: “flood, rushing water, slew the race of giants — they suffered terribly: that was a people alien to the Everlasting Lord”. The book of Genesis also talks about a flood, describing Noah in the ark with his family for forty days and forty nights. Another concept that can be viewed as Christian is the idea of sharing treasure, giving away rings. This generosity is what Christianity promotes.
Hrothgar warns Beowulf about the sin of excessive pride and tells him that sharing treasure is the right way for a king to live. However, this sharing is not unconditional. In exchange for the treasures, the lord expects his thanes to back him up in the time of troubles: “A king ought by the good deeds, by giving splendid gifts, to make sure that later in life beloved companions will stand by him, that people will serve him when war comes.
These are two good examples of how biblical references are used in Beowulf. The biblical references were made to influence the audience of the time. Christianity was a fast spreading religion and the people of Christianity wanted this to be worldwide. So the use of the biblical references are made to help spread the word of Christianity, and to make everyone think it was the right way. Just to make it look more glorious.