There was this movie that starts off with some kind of detective or priest investigating something. He goes into this basement/catacomb room and there are a couple naked dead bodies on tables (don't remember if metal or stone). Anyway he ends up going to this town where there is a teenaged boy (either 12 or 14 I think) who is supposedly some kind of coming of christ or reincarnation. The devil or demon is after this boy to either corrupt him or take over him. Initially the devil/demon can't touch the boy or go directly into the light until he has murdered enough people to make up for the years the boy has spent in the light/darkness (which is either 6 or 7 years each so 12 or 14 murders each). The devil/demon is hiding in some sewers which the boy often hangs out near one of the drain exits. He tries to touch the boy's shoulder but can't because he hasn't killed enough. Some of the deaths involve a police station where he takes over the dogs if I remember correctly. Also I recall a neighbor/old lady being controlled and climbing an electric pole to cut the power so the devil/demon can go into the home (which had lights on to prevent him). Eventually he succeeds at taking the boy and the priest/detective and the boys mother go after him through the sewers (which is deduced where he is going). It ends up leading to a church/sanctuary where the devil has the boy on the altar and is about to stab him with a knife (the boy was shirtless and had some kind of pattern/symbols drawn on his chest; or they were being drawn by the demon/devil). The demon/devil is shot and the boy saved. The boy himself was not evil, he was in limbo between the years of light and years of dark that was supposed to determine the fate of man or something and the demon/devil was trying to make that flux to the dark instead of the light. This was a "modern time" movie and mostly took place in the down.
As far as when I saw this movie, it was on TV and aired either right before or right after "Don't Look Under the Bed" (but not necessarily on the same channel). I can't seem to find how often that movie was aired, but it would most likely have placed this as being on TV on Oct 9th, 1999 or shortly after that as that was the air date of "Don't look under the bed". As far as I can tell, this is not the Omen or The Prophecy or the Ninth Gate.