Jehovah’s Witnesses (Disfellowshipped?)

     I continue to hear these stories of brothers and sisters from different halls being disfellowshipped from their congregations. I’m curious as to the biblical foundation which this practice is upheld.  My problem is with the overall concept.  How can a group of elders pass judgment against a person for committed sin.  Jesus told the Pharisees”those without sin cast the first stone” when making a case for a prostitute. So how is that a body of elders, who are not perfect but sinners, cast stones to individuals that kick them out of the congregation and separate them from fellowship with their brothers and sisters at the hall?  Not to mention, is the Church not likened to that of a hospital for sinners? Then they have the mentality that they have the abilityto tell if a person is “truly repentant” for what they had done to allow a person to be reinstated.  Here’s another thing. This is just my own two cents. What separates sin? Meaning, where is the line of sin and really bad sin.  Some sins are overlooked and not dealt with at all. Now other sins are placed on a much higher level. I’m here to tell you if a body of elders are going to kick people out of the kingdom halls for big sins then they need to throw everyone out for all the other sins. The Bible states that if we are guilty of breaking even one law then we are guilty of breaking them all. We all have sinned and have fallen short of the Glory of God. God doesn’t see different levels of sin. He despises all sin equally. Can anyone show me where there is a hierarchy of sin in the Bible? We need to be showing the world God’s love and Grace. An exclusive club that kicks people out for being, well….people, does not show Gods Grace. It only shows it to be an exclusive cult. I don’t know could someone please bring some light to this subject for me.