Double feature finished! I watched The Church, followed by Prince of Darkness. Thank you for the recommendation! It was quite fun. These films work very well together. They both cover similar ground: An ancient evil beneath a church, satanic corruption, the 1980s, etc. There's something to be said for both movies involving people taking the reigns after the old ways fail and trying their best in the face of the apocalypse. Something about that speaks to me right now.
Though he only wrote the screenplay, Dario Argento's flair shines through in The Church. Visual style, excellent special effects, and an excellent last half-hour make something spectacular out of what could have easily been a boring giallo gorefest. It has its schlocky moments, but not enough to detract from the movie. The demon scenes are fantastic and spooky. I think what makes them so strong is how mundane it looks. The Satan sex scene doesn't look like a dream. It just looks real and that's terrifying. If you're down for gory, apocalyptic, biblical horror, The Church is worth the time. Especially when paired with its American cousin, Prince of Darkness.
I liked Prince of Darkness quite a bit. Combining theoretical physics and ancient lore without mixing them was a cool idea. The concept of a broadcast from the future beaming into the brains of those who are charged to fight the Anti-God is pretty damn cool. The performances are solid and the pacing is impeccable. That being said, I can see why this is the least known of Carpenter's Apocalypse Trilogy. The ingredients of Prince of Darkness are nothing special in the grand scheme of 80s horror, incorporating demonic schemes, rot-faced possessed girls, exactly one black character who manages to steal the show, a cameo from a rock star, Victor Wong as strange mentor, and Donald Pleasence as the smartest man in the room that no one trusts. Compared to The Thing, which is so much itself, and At the Mouth of Madness, which is full-on H.P. Lovecraft, Prince of Darkness just doesn't stand out. It's a solid movie and it's still Carpenter so it's a ton of fun to watch, but there's something missing.
Over all, I would recommend other folks trying the double feature idea with these movies. They're both strong enough to stand on their own, but they play off each other very well.