Church membership and church discipline are 2 biblical ideas that must go together. For this reason, the best way to affirm this needed duo is to recommend a small, simple, and clear book for both of them. I have known Jonathan Leeman a long time and this brother thinks through these issues as well as anyone I know. He has written both of these books on Church Discipline and Church Membership and they are meant to be received together, two of 9 Marks most recent works. I highly recommend every pastor to read them, then buy several copies to give out to church members.
You can find them at a good price here: Membership and Discipline.
