Robin Hood: I for one would rather die than spend my life in hiding. The Sheriff calls us outlaws, but I say we are free! And one free man defending his home is more powerful than ten hired soldiers. The Crusades taught me that. I will make you no promises, save one: that if you truly believe in your hearts that you are free, Then I say we can win!
Guy of Gisbourne: Why a spoon, cousin? Why not an axe?
Sheriff of Nottingham: Because it's dull, you twit! It'll hurt more!
Sheriff of Nottingham: Locksley! I'm gonna cut your heart out with a spoon.
Robin Hood: Then it begins.
Sheriff of Nottigham: That's it then! Cancel the kitchen scraps for lepers and orphans, no more merciful beheadings, and call off Christmas!
Sheriff of Nottingham: [To some prostitutes.] You - my room,10:30 tonight. You - 10:45. And bring a friend.
Will Scarlett: There was a rich man from Nottingham who tried to cross the river. What a dope, he tripped on a rope. Now look at him shiver.
Robin Hood: Look. Mistletoe. Many a maid's lost her resolve to me thanks to this little plant.
Azeem: In my country, we talk to our women. We do not drug them with plants.
Villager: But what about our kin? Sheriff's taken all they got too!
Robin Hood: Then by God we take it back.
Azeem: English! English! Behold Azeem Edin Bashir Al Bakri! I am not one of you, but I fight! I fight against a tyrant who holds you under his boot. If you would be free men, then you must fight. Join us now! Join Robin Hood!
Will Scarlet: Fuck me! He cleared it.
Answer: The white robes, reference to "the old ways", and pentagram across the map when the Sheriff meets the Barons suggests per-Christian Druidism; the upside down crucifix certainly implies Devil-worship. These two spiritual paths are, by nature, mutually exclusive. In short, a fictional pseudo-witchcraft invented for the film, yes.