Beowulf also demonstrates an interesting mix of Christian belief with pagan views of the world. Throughout the text Beowulf and others talk about wyrd which is the Anglo-Saxon view of fate. They are very aware of their actions and the glory they hope to gain from their choices in the actions they take, but over it all, they see fate as being a dominating force. It is fate that Beowulf learns of Grendel; it is Hrothgar's fate to accept the help from Beowulf; it is fate that Beowulf dies after a fatal wound from the fire breathing dragon.
On the other hand, the characters talk about God, and pray for God's good providence in their lives. These comments seem to be in opposition to the concept of wyrd, but when we consider that the story of Beowulf is a pagan story, but was only passed by oral tradition until it was first written down, in a then Christian culture, it makes sense that the Christian views of God find their way into the story.
Both of these philosophies of life are presented throughout the text, both before battles, during battles, and after them. The audience of original story would have understood the idea of wyrd's role in life, and the later Christian audiences understood a blending of fate and God. Even a modern audience can appreciate these philisophies.
Considering the historical context of the poem, I think the best answer to your question is that Beowulf portrays a philosophy that life is not more important than honor, loyalty or reputation. Beowulf and many other celebrated heroes (spoken of in the text) were willing to fight (to the death if necessary) to save the lives of strangers. Beowulf comes to Hrothgar's aid because of a few reasons. First, he has a debt to repay Hrothgar on behalf of his father. Second, he knows he is the only man who can actually fight and probably kill the monster that plagues Herot. Finally, he knows when he is victorious, he will be given riches and respect, and his name/fame will spread even further.
Additionally, Beowulf's men are willing to fight with him and for him by order of the comitatus. Both historically for Anglo-Saxons, as well as for the characters of this poem, clearly it was most important to live so as to leave a legacy behind. If this meant dying in the process, so much the better.