One of the best-crafted possession films but in a rightfully dying genre
*Spoilers*
We had the godfather of demonic films, ROSEMARY'S BABY in 1968. Not quite possession, but demonic certainly.
Then we had THE EXORCIST in 1973. Full on possession film, if not the definitive one.
A few years later THE OMEN in 1976, another demonic film continuing similar themes of the previous two.
But since then, it's been a mess. The idea of demon possession as a story-driver has been exhausted, people! It's like JAWS - an extremely powerful idea but only with a story shelf-life of one film, just look at the sequels!
Attempts to breathe life into the idea of demon possession include the interesting but not scary THE EXORCISM OF EMILY ROSE, the god-awful mess of horror film cliches called THE CONJURING, Blair Witch-inspired PARANORMAL ACTIVITY. Some of these were novel angles in the demon genre, but I don't think any will ever reach the quality of the first three films I mentioned.
And I understand the shift of focus toward the dichotomy between religious faith and atheism, but as this film shows, the arguments presented in the story are simply part of a rigged debate when fictional evidence for demons is chucked in: So you're not a believer, fellow audience member? Well how do you explain Hopkins' demon-possessed face, you know, the one they made using cgi?
Not only that, but theological discussion - while interesting and ethically important in the real world - is simply not scary. It intellectualises something that needs to terrify and spook us.
Just admit it, people, the demonic-possession era is at an end.