How we cite our quotes:
Let not thy mother lose her prayers, Hamlet:
I pray thee, stay with us; go not to Wittenberg.
"Wittenberg" is shorthand for "Protestant," since that's the city and university where Martin Luther wrote his Ninety-five Theses. But the play can't seem to make up its mind about whether or not the play is set in a Catholic or Protestant world—just like England itself, throughout most of the 16th century.
I am thy father's spirit,
Doom'd for a certain term to walk the night,
And for the day confined to fast in fires,
Till the foul crimes done in my days of nature
Are burnt and purged away.
Hmm. This is interesting. The Ghost not only claims to be Hamlet's "father's spirit"; it also suggests that it's a Purgatorial ghost. Purgatory was often imagined as a fiery place where souls "purged away" their sins before going to heaven. Major difference, though: Purgatorial spirits returned to ask loved ones for prayers that could help them reach heaven faster. This ghost? He's a little more interested in revenge.
Revenge his foul and most unnatural murder.
Purgatorial spirits weren't in the habit of asking living relatives to murder other people (murder being a major sin for both Protestants and Catholics) to help them get to heaven. That's more along the lines of a vengeful ghost. Is Shakespeare just picking and choosing? Or is he purposefully weaving together multiple literary and cultural traditions?