Some churches concentrate far too much on the OLD instead of the NEW revelations of God. Pentecostals notably do this, along with other groups who seem to use it to maintain legalistic bondage of their adherents.
It is all very well to say that we need to understand the old before we can understand the new, but again, this is used to further the purpose of the deception that is inherent in the old covenant which keeps the mind set on flesh and death instead of Spirit and life.
To be continually quoting from the old, will detract from the intent and purpose of the NEW, will hold people’s thoughts and attention to that awful trio of law-sin-death. If you ask church goers about the status of the ten commandments for example, you will most probably find they are still caught up in paying homage or lip service to the old covenant.
This, along with wrong teachings about even the most simple of doctrinal matters, continues to be a source of confusion and distraction to many who then can never gain a clear picture of the Christian faith.