Almost two months after I've seen this movie, I'm still trying to decide what I think of it. It's certainly effective, accomplishing everything it sets out to do. Robert Eggers is scarily self-assured at the helm of his first feature film, creating an atmosphere of uncanniness and spiritual dread that is unwavering and flawlessly oppressive. If The Exorcist is a horror movie for Catholics, then The Witch is a horror movie for Protestants: Because the individual (not the institutional church)…