This is always a sticky subject. No one likes doing it, but as Calvin points out, church discipline is an absolute necessity to maintain the health of the church:
Accordingly, as the saving doctrine of Christ is the soul of the church, so does discipline serve as its sinews, through which the members of the body hold together, each in its own place. Therefore, all who desire to remove discipline or to hinder its restoration––whether they do this deliberately or out of ignorance––are surely contributing to the ultimate dissolution of the church. For what will happen if each is allowed to do what he pleases? Yet that would happen, if to the preaching of doctrine there were not added private admonitions, corrections, and other aids of the sort that sustain doctrine and do not let it remain idle. Therefore, discipline is like a bridle to restrain and tame those who rage against the doctrine of Christ; or like a spur to arouse those of little inclination; and also sometimes like a father's rod to chastise mildly and with the gentleness of Christ's Spirit those who have more seriously lapsed. When, therefore, we discern frightful devastation to threaten the church because there is no concern and no means of restraining the people, necessity itself cries out that a remedy is needed. Now, this is the sole remedy that Christ has enjoined and the one that has always been used among the godly.John Calvin, Institutes of the Christian Religion, Book IV, Chapter XII, I.
