After director David Gordon Green revived the Halloween franchise with his trilogy of sequels, Universal tapped him to do the same thing with The Exorcist–make a direct sequel to the original film, and get a modern franchise going. And now we have The Exorcist: Believer, positioned as the first entry in a new trilogy (box office performance pending, presumably).
Despite that franchise plan, Believer functions in a fairly standalone way, allowing for the possibility of continuing the story while also concluding things in a way that would work pretty well if they don’t make any others. It’s hard to talk about it in these vague terms, though–it’s time to get spoilery.
Warning: This article contains spoilers for the entire plot of The Exorcist: Believer, including the ending.