The Belgic Confession of Faith
Article 32: The Order and Discipline of the Church
We also believe that, although it is useful and good for those who govern the churches to establish and set up a certain order among themselves for maintaining the body of the church, they ought always to guard against deviating from what Christ, our only Master, has ordained for us.
Therefore we reject all human innovations and all laws imposed on us, in our worship of God, which bind and force our consciences in any way. So we accept only what is proper to maintain harmony and unity and to keep all in obedience to God.
To that end excommunication, with all it involves, according to the Word of God, is required.