To the Devil is a decent little film. In its favor, it has Christopher Lee in a commanding performance as a rogue priest, Father Michael who appears to be playing for another team. [Satan, anyone?] He and his minions have nefarious plans for sweet Catherine, played perfectly by Nastassja Kinski [Cat People]. Her only hope is an American occult novelist, played nicely by Richard Widmark [Coma, Murder on the Orient Express], who tries his best to deliver her from evil. Yep, it's classic stuff.
The second thing it has going for it is a few good special effects and the creepiest little "satan baby I've seen in a long time. These elements add the needed feeling of dread to the film. There's not much more to say about this one. The story is far from original but it's a great one to watch on a lazy Sunday afternoon. If you're a fan of the classic "giving birth to a devil baby" genre, then this one is definitely your cup of tea.
For more info check out the film's entry in IMDB.