I’m not certain if this qualifies as a good Christian film, but it functions exceptionally well as a horror movie. It seems almost destined to struggle for acceptance, since audiences who identify as Christians generally don’t respond favorably to psychological horror, and fans of the horror genre are typically turned off by movies promoting Christian values produced by people of faith. Consequently, there isn't really a sizable group that would naturally enjoy something like this, and it appears those involved were aware of that fact, creating it purely for the appreciation of however small a number of viewers who might connect with it. I’m unsure whether it truly intends to be considered either a successful Christian movie or a compelling psychological horror film; regardless, it manages to achieve both goals. Considering its subject matter—demonic possession—the film is surprisingly grounded in reality. I can say this having worked as a guard in prisons and mental facilities. There are some very small inaccuracies, but they’re either required for the story or implemented for safety precautions (it's not necessary for everyone to know precisely what security protocols are actually used in a prison). Interestingly, there is already a nearly identical German film called "Der Totmacher" (The Deathmaker). I doubt anyone involved with this movie has seen it, though they’re essentially the same story, because that German film's script is entirely based on transcripts from an actual psychological evaluation of an actual serial killer. That illustrates just how closely connected to reality everything feels.

Source on TMDB