At the film's climax, the Warrens, the husband, and the deputy need to get back into the house quick-like. When they can't open the door, instead of slamming their shoulders against it like they have been trying all movie, the deputy tells the rest to back off and blows the lock (and knob) off the door with a shotgun.
The fact that this movie was rated R only because it had an atmosphere that was deemed too scary for a PG-13 film.
The climax of the second movie. Lorraine goes up against a high-ranking demon that's been psychologically torturing her for years and sends it packing, all to save her husband and friends.
The defeat of the demon also echoes the ending of the original film - "Your name gives me dominion over you, demon, and I do know your name. You are Valak, the defiler, the profane, the marquis of snakes. In the name of the father, the son and the holy spirit, I condemn you back to hell."