Not everyone likes this movie. It is still one of the best "you have to be thinking" movies about Satanism ever made. The fact that it doesn't have MTV-era jump cuts or gore every seven minutes is irrelevant. Also, speaking as someone who actually KNOWS Satanists, the (spoiler warning!) portion of the film where the Brotherhood exchange their old bodies for those of preadolescent children, it has some genuinely scary scenes. The section where (second spoiler alert) Strother Martin orchestrates the changeover is almost hyper-real in that it uses very few special effects, a hallmark of this film. McEveety was seldom given a big budget but was often effective. It worked in this case, too.