Just think about all the people that you would like to have revenge on. This is what I call... a "pep talk" for that action. Coleridge's sonnet promotes the idea of an eye for an eye (via death). The Raven is merely the middle man for the impending action. Look at this:
Where then did the Raven go?
He went high and low
Over hill, over dale, did the black Raven go.
Many Autumn, many Springs
Traveled he with wandering wings:
Many Summers, many Winters
I can't tell half his adventures.
The Raven must represent death... and of course death is obligated to be everywhere in one way or another touch everyone. It's people who decide how death is acheived. In this case it is revenge. So what do you think death represents.