Beowulf is an Old English heroic epic poem. This means that it is a lengthy narrative poem that tells heroic tales. Such heroic poems often contained lessons and served as moral examples. Remember that in Anglo Saxon society, there were no books, so the Anglo Saxons passed on stories and histories through oral tradition. This is how they “taught” lessons to future generations. Later, these oral stories were written down, but by this time, the people writing them down were usually monks, so the Christian viewpoint became interspersed into the pagan legends. This is why you find a type of dichotomy in Beowulf – the hero’s deeds mixed with Christian teaching, or didacticsm.
In Beowulf, there are many stories and lessons in addition to the exploits of Beowulf himself. If you go back and read these stories, you will see that many are meant as teachings. Think about it in the same way as some of the Bible stories in the Old Testament. The story of David and Goliath, for example, is a story, but at the same time, it is meant to teach something – the bigger they are, the harder they fall, especially when they let pride get in the way!
Read Beowulf at the link below and see the analysis on eNotes.