Are you familiar with the God of the Abraham, Issac and Jacob? The Israelites? That is the Almighty which I serve. I am one of Her angelos.
[ooc: Aziraphale uses the ancient Greek word 'angelos' here, which is literally translated into 'messenger', from which English gets its word, 'angel'.]
I do hope that won't be a problem for you. I'm enjoying your company.
[ooc: after another heavy sigh]
While revenge usually leads to wrath, I'd say fighting against tyranny is pretty righteous.