Still, we even think that church membership is some random and modern phenomenon that we do to look like other social groups. The church at Corinth had to have some sort of corporate understanding of someone being a covenant and community member or else they would have had nothing to excommunicate people from. Paul says of wayward church members that he "handed them over to Satan" [1 Cor 5].
This is a fragile, yet needed discussion. There are some pastors and elders that need to grow a backbone. 1 Corinthians 5, Matthew 18, and the pastoral epistles are replete with examples of how the church and its members must be taken seriously. Preachers who pad their membership roles or see how many they can stuff in the bleachers so that they can get on TV or write a book - these guys are earning bonus points for the "False Teacher of the Year" award.
All of this rabid tangent means nothing unless it can positively be fleshed out and not merely negatively called out. So, here's a beautiful chart I recently found from one of Wayne House's books.
He will build His church. He will purge and sanctify His people.