"holily"

Definition: i.e., with the approval of God.
Lady Macbeth understands that her husband would prefer to become a divinely appointed monarch. As we see in Macbeth and in the second tetralogy of history plays, Shakespeare is very interested in the topic of divine right and seems to support wholly the theory that a king cannot be a good ruler unless he is divinely appointed. For more on this, please see my essay, Representations of Kingship and Power in Shakespeare's Second Tetralogy.