Truth

The Shaper has an interesting role in the book, Grendel. His words contribute greatly to the pride the Danes have of themselves because he gives them this idea that they were glorious in their past and they are glorious now. However, most of the "history" the Shaper sang about was false and inaccurate. But this is who the Danes believed; the things the Shaper told them was the only thing they knew, therefore they didn't question what they knew was the truth.
Throughout the entire book though,  the truth was often manipulated or not fully told. Even omitting the truth is still allowing people to formulate a false perception. It's very easy to believe someone you love or believe a source that is being provided to you from someone who has your best interests. A perfect example of this in Grendel is the whole purpose behind writing Grendel. The book is supposed to give readers a chance to understand both sides of the story. When reading Beowulf, many readers form the conclusion that Beowulf is the good guy and Grendel is the bad guy. It's easy to assume this since you don't have the other story, just how it was easy for the Danes to believe the Shaper when he portrayed them as wonderful beings. By reading the book Grendel we see how the Danes aren't as heroic as they make themselves seem to be. If anything they are more barbaric and monstrous than Grendel. Ultimately, it's safe to say that what you're being told is not necessarily the truth or all of it.