At the first communion, Jesus had Judas Iscariot with Him. Did Jesus not know how to discipline? It is not the pastor's duty to discipline at the communion service. If the pastor has issues with a "member", I hope the disciplining would be before communion. I would think there would be a better time and place. The pastor is not held accountable, if in ignorance, he lets someone take communion who claims to be a saved/baptized follower of Christ. It is his duty to reiterate what Paul wrote about taking communion "For he that eateth and drinketh unworthily". Also, "But let a man examine himself" Where does it say the pastor is to do the examining. Paul was rebuking for turning communion into a drunk fest, today it seems some pastors are turning it into a power trip!
We are told to separate light from dark, period! Someone is always trying to separate for personal reasons whether it is blacks from whites or lets make the women sit on one side of the church and men on the other, etc. etc...and doing it in the name of Christ.
The body of Christ is not supposed to have any schisms, but some have found a way. When we truly understand who makes up the body of Christ and who the church really is, not a building, then we will realize how goofy this all sounds. It is a called out assembly, and yes it has to have a locale, we can't all meet in Jerusalem or Mecca. But it is a called out assembly....called out from the wicked world, not called out from separate church buildings.