There have been many religious movements in history. Some have had far greater impact than others and some are still going strong.
In my opinion, I think ANYTHING that is added to or taken away from scripture is something that isn't following true Christianity. True Christianity is really very basic, and I look at it as anything that follows teachings of Jesus or the apostles. Or Moses as in the Ten Commandments of Course, but more so the two greatest commandments given by Jesus.
If there is a practice, that you don't see being commanded or done in the New Testament, it is very likely something that has gone off the simple path. If the interpretations fall to some leader of some kind, no matter at what point in history, then its likely more of a man made tradition that has been started. Great question!