Church membership is a concept that while not explicitly articulated in the Scriptures is assumed and supported. Many of the New Testament letters were written to local congregations with instructions as to how they were to deal with their life together (for example, 1 and 2 Corinthians, Galatians, and Philippians). Even though church membership is common in churches today and throughout history, I’ve found it helpful to broaden out the answer to help fill out my reasons for why we have church membership.

Is church membership biblical? Is it important? Yes, I believe so. Here are four main reasons why.

First, there are theological reasons. In other words, there are certain truths about who God is and what he has done that require membership language and the practice of membership.

When God caused you to be born-again, he established a new relationship with you. Formerly, you and I were separated from God in our rebellion, but God, being rich in mercy (Eph. 2:4), has made us alive and brought us into his family by “adopting us to himself as sons through Jesus Christ” (Eph 1:5). By grace, "He has delivered us from the domain of darkness and transferred us to the kingdom of his beloved Son" (Col. 1.13). Those who were formerly far off “have been brought near by the blood of Christ"  (Eph. 2:13). To say that we are part of the kingdom of Christ, the body of Christ, the people of God, or God's family is another way of saying we have become members of the church. This is why 1 Corinthians 12:13 tells us that “in one Spirit we were all baptized into one body."

Membership in God's universal or collective church happens when God the Holy Spirit unites us spiritually to the body of Christ throughout history. However, membership in the local church happens when we unite together with other believers in a physical location. This is what I am emphasizing here. Church membership in a local church presupposes and necessitates membership in the universal church through conversion. Church membership reflects the theological truth of the gospel.

Second, there are covenantal reasons. A covenant is an agreement or a relationship with obligations. Most commonly we think of the marriage covenant. There is an agreement between a husband and a wife that has obligations pledged or vowed to one another. The relationship is undergirded by an oath. When we become a Christians, we become a part of the New Covenant. The New Covenant is the legal oath that God has made with his people. In a nutshell, God promises to be our God, forgive our sin, give us his Spirit, write his law upon our hearts, and dwell with us forever. Our response, upon entering into this covenant, is that we will follow him and be faithful to him. In other words, to use the language of Jeremiah, “I will be their God, and they shall be my people." (Jer. 31:34)

This probably seems straight-forward. You become a Christian, and things change. You have a relationship with God that brings a responsibility to follow him. But we often forget that this covenantal relationship with God also brings us into a relationship with others, where we also have responsibilities. In other words, God has not only called us into a covenantal relationship with himself but also with others. This is why we must have church membership. When we join a church, we agree, or pledge, or promise together to take responsibility for one another. We agree to a set of doctrinal specifics. We agree to work together to advance the gospel. Membership expresses our covenantal relationship.

Third, there are evangelistic reasons. By this, I mean that meaningful membership in a church actually communicates something of the value and shape of the gospel. What do I mean? Membership is a congregation's declaration to one another and to a watching world what a true confession and confessor of the gospel looks like. One of the primary responsibilities of the gathered congregation is to evaluate the profession of faith in its prospective members and then to regularly evaluate it in the lives of their current members (Mt. 18:15ff; 1 Cor. 5:1-13; 2 Cor. 2:6-11). In other words, the congregation, the members, declare to a watching world, This is a right confession of the gospel." And, by virtue of their ongoing membership, "We stand with this brother or sister in how they are representing Jesus in the world."

Meaningful membership attends our gospel witness. Membership communicates the people and the message of the gospel to a watching world. 

Fourth, there are practical reasons. To do the things that we need to do as a church, there must be some way to discern who we are talking about. I mentioned your responsibility as a Christian; does that extend in the same way to every single Christian living on the planet? No, of course not. You and I can't possibly fulfill the covenantal obligations with brothers in sisters living in Beijing, Baghdad, Toronto, and Omaha. Our church can't even fulfill the requirements to every Christian in Omaha. Similarly, pastors are called to keep watch over the flock, knowing they will give an account (Heb. 13.17). Whose flock? What flock? How do we know who we are going to give an account for? Peter says to shepherd the flock of God that is among you (1 Pet. 5).

This is also seen in the concept of church discipline. “When Jesus instructed his followers to seek out the brother who has sinned (Matt 18: 15- 21), he was presupposing such an integrated conception of body membership. Actions of reproach and, ultimately, exclusion are to occur within the arena of a specific and identifiable group of people" (Dever, The Church).

In our church, we do this with a physical list and a membership directory. This helps us as members with a resource to pray through and be reminded who we are responsible for.

Some may bristle at the concept of formal membership, but, in addition to the obvious practical benefits, there seems to be a historical and biblical practice.

[P]hysical lists of members may well have existed in the earliest Christian churches. Clearly, the keeping of lists was not unknown in churches. The early church kept lists of widows (1 Tim. 5: 9). God himself keeps a list of all who belong to the universal church in his book of life (Rev. 20: 12). Paul assumed that the Corinthians had identified a “majority” of a particular set of church members who were eligible to vote. (Dever, The Church)

Meaningful membership helps us to see who we have this day-to-day New Covenant relationship with and who we are immediately responsible for. Knowing who we are accountable to and for helps to clarify what and how we are doing. Membership helps us to see who we are accountable to and responsible for.

Church membership must be a priority for Christians because God has not only called us into a covenantal relationship with himself, but also with others. Is church membership biblical? Is it important? Yes, I believe so.

Editor's Note: This post originally appeared at Erik's blog (Ordinary Pastor) at The Gospel Coalition.