In my experience most people have a very weak understanding of church membership. Rather than seeing their membership to a congregation as an interdependent commitment to a body (think of Paul's metaphor in 1 Corinthians 12), they view membership through the lens of our consumer culture. They associate "membership" in a church as a religious version of the relationship one has with Costco, Netflix, or AmazonPrime.
To combat this some churches have undertaken the admirable task of elevating what a commitment to a congregation means. They've clearly articulated expectations and formalized the process of church membership in a manner that reflects the gravity and biblical roots of the idea. In addition, the process of membership is also a way of protecting the flock from wolves who seek to prey upon God's people. As reported in this interview with Ken Sande from Peacemakers, membership is both a congregational and legal means of protecting the church.
But can this pursuit of security go too ...1