The church is an organism, not an organization.
Ecclesiology is one of the more contested topics in theology. One can see this from the various polities that prevail. Episcopal, presbyterian, congregational all conceive of the church in a slightly different way. But even more basic than this is the idea of the church as an organization, an institution, and one that stands as the dispenser of grace to believers. The Roman Catholic Church, the Orthodox church, and some expressions of Protestantism hold to such a view. It is old, but as George Weigel has said, “That something is antique in the Church, however, does not mean it is necessarily good, or true, or an aid to mission.”
One of the prime manifestations of this institutional ecclesiology is the belief that the church is necessary for salvation. Cyprian of Carthage is famous for his much-quoted statement; “He cannot have God for his father, who has not the Church for his mother.” This may be a clever parallel to the biological necessity of children requiring both a father and a mother, but is it biblical? The metaphors and pictures used for the church in the New Testament are many, but several are dominant. The church is the body of Christ, it is a holy temple, and it is the bride of Christ. Of the 96 pictures of the church found in Paul Minear’s exhaustive study Images of the Church in the New Testament, none of them refers to the church as the mother of believers. Styling the church as the mother of Christians fits into the hierarchical paradigm of the church as existing apart from the body of believers, and directing the members of the body, yet there is simply no biblical data to support the idea of the church as our mother.
I have made the statement often that the church is not the conduit of salvation, it is the result of salvation. I encounter opposition at times when I say this. Partly, it may be due to some misunderstanding of what I’m saying, but for others it is because they hold to an institutional ecclesiology that is absent from the New Testament. What I mean by my statement is that when one is saved, one is made a member of the body of Christ—the Church. It is not optional or a second act of joining that is required. It is in fact redundant to say “I am a Christian” and “I am part of the Church.” These two statements affirm the same thing. To be brought into God’s family, to be converted, is to be made a member of Christ’s body. The Gospel is the power of God unto salvation, that is, salvation is the result of believing the gospel, of faith in Christ. When one believes, that person is instantly made a member of the body. The proclamation of the gospel cannot be restricted to some official act of the church or any hierarchy. It is the Word that forms the church, by which we are born again. (1 Pet. 1:23). What I refer to is not membership in a particular local church. Indeed, membership in a local church is predicated on the fact that one is already a member of the one body, that one is already a Christian.
Clericalism would say that the rites and sacraments of the church are the thing that makes one part of the church. A formal submission to the authority of the institutional church is thus required. Does “exercising the keys” (Matt 16:19) provide an example of the necessity of the church? In the remainder of the NT, we find no example of any gatekeeping that hearkens back to this. Indeed, in one incident involving Peter himself, he rebukes Simon the Magician for his belief that he could purchase God’s gift with money. But Peter pronounces nothing other than what Simon himself confessed. He only recognizes the state of his heart, he does not withhold or grant anything.
Nor should anyone mistake this for participation in the life of the church. Regularly gathering with other believers, partaking in the Lord’s Supper, hearing the word preached and expounded, are all things the NT enjoins believers to do. But these, too, assume membership in the one body of Christ. These are activities of believers. No one should mistake these imperatives for the idea that the church is the arbiter or dispenser of salvation.
The gospel itself is the way into the church. Eternal life comes by believing the message of salvation, of pardon in Christ. It is a message of him who alone is the way, the truth, and the life. When we come to him, we are made members of his body. We dare not insert the church in the position of mediating between God and man. According to the New Testament, the one mediator between God and man is Christ Jesus. To ask whether the church is necessary for salvation is to misstate the question. Salvation necessitates the church, because to be saved is, ipso facto, to be in the church. The church cannot deny what Christ has given, and membership in the body comes as the birthright to all who trust in him.
 George Weigel, Evangelical Catholicism: Deep Reform in the 21st Century Church, (New York, Basic Books, 2013), 100.