While many Christians would never say what Carl said, they nonetheless act or behave as though the church were indeed an unnecessary human institution. But is that what Scripture teaches about the church? Hardly. In this brief, introductory survey, we will see that had Carl understood what Scripture says about the meaning and marks of the church, he would have realized that he could not denounce the church without also denouncing her Lord.
While Scripture refers to the church as those called by God into covenantal union with Him, Scripture also employs a rich array of metaphors to refer to the church: the body of Christ (I Cor. 12:27; Eph. 1:23; Col. 1:18), the bride of Christ (Rev. 21:2, 9), the fullness of Christ (Eph. 1:23), the household of God, the pillar and ground of the truth (I Tim. 3:15), and the heavenly Jerusalem (Heb. 12:22). When we speak about those whom God has called in this way, we are speaking about the invisible church which, as The Westminster Confession (XXV, 1) says, consists of the whole body of believers, in heaven or on earth, who have been (past), are (present), and shall be (future) united to Christ (Eph. 1:22; 3:10, 21; 5:23-32; Col. 1:18, 24; Heb. 12:23).
But Scripture not only speaks of the invisible church; it also speaks of the visible church, that is, those who, in a particular place (or places) and at a given point in time, profess faith in Christ (Acts 5:11; 11:26; Rom. 16:4-5, 23; I Cor. 11:18; 14:19, 28, 35; I Cor. 16:1, 19; II Cor. 8:1; Gal. 1:2; Col. 4:15; I Thess. 2:14; II Thess. 1:1, Philemon 2; Rev. 2:1), along with their children (Matt. 19:14 and Luke 18:16 together with Matt. 3:2 and Matt. 13:47; also compare Eph. 1:1 with Eph. 6:1-3 and Col.: 1:1-2 with Col. 3:20; see also I Cor. 7:12-14).
The difference between the invisible and the visible church, therefore, is really a matter of perspective: since the secret things belong to the Lord our God (Deut. 29:29), and since only the Lord knows those who are His (II Tim. 2:19), only God ultimately knows each and every member of the invisible church. Thus, from the vantage point of the divine perspective the exact members of the invisible church are known. From the vantage point of our human perspective, by contrast, the exact members of the invisible church will never ultimately be known on this side of eternity (which is simply to say that it is invisible to us). Put simply, the invisible is invisible to us but not to God. There are three reasons why this is the case.
First, some who are members of the invisible church may never become members of the visible church because it would be physically impossible for them to do so (e.g. someone who finds a Bible on an uninhabited island, comes to faith in Christ, but never again comes in contact with civilization so as to be able to join the visible church).
Second, some true believers (i.e. actual members of the invisible church), due to personal inconsistency, may, at times, betray their espoused faith thus obscuring the fact -- from a human vantage point -- that they are really members of the invisible church. They may act inconsistently with their espoused faith either by failing to join the visible church or if they do join the visible church, by simply acting as though they were unbelievers.
Third, unbelievers (those who are not actual members of the invisible church) may be parading impostors who, from every human appearance, act as though they were believers (members of the invisible church), when, in fact, they are not. In the words of Christ, such unbelievers are tares among wheat, bad fish among good fish, foolish virgins among wise virgins (Matt. 13:24-30; 47-50; 25:1-13), and will -- at the appointed time -- be separated from true believers (Matt. 13:30, 50).
Thus, the members of the visible and invisible church are not necessarily identical; that is, not all members of the visible church may be members of the invisible church and vice versa. To say that the membership of the invisible and visible church is not identical, however, doesn't change the fact that God has always preserved a true remnant of those who are truly His (I Kg. 19:18) and that the gates of hell cannot prevail against the church (Matt. 16:18). Because the true church actually manifests itself "through those who are living in the world at a particular time and place" (Williamson, G.I., The Westminster Confession of Faith for Study Classes, p. 187), the true visible church is not one whose members are identical to the members of the invisible church. Rather, the true visible church is one that manifests the marks of the church.
First, each of these marks is ever and always to be subordinated to and judged by the supreme standard of Scripture -- even apostolic doctrine (Acts 17:11). Hence, the true church is really characterized by one supreme mark (true submission to Scriptural authority) which, in turn, manifests itself in adherence to apostolic doctrine, proper administration of the sacraments, genuine fellowship, and heartfelt prayer.
Second, submission to Scriptural authority and the four marks enumerated in Acts 2:42 imply yet another mark: church government and discipline. After all, Scripture itself informs us (a) that elders are the ones who are given charge to exhort the fold in sound doctrine (i.e. truly Biblical and apostolic doctrine) and to refute those who contradict such doctrine (Tit. 1:9); (b) that the sacrament of communion, in order to be administered properly, must be given only to those who examine themselves and thus cannot be administered indiscriminately (I Cor. 11:27-34); (c) that we are to identify, judge, withhold fellowship from, and excommunicate so-called believers who unrepentantly persist in sin (I Cor. 5:1-13); and (d) that we are to pray for our elders so that they may lead us with godly wisdom (Col. 4:2-3), and that elders are, in turn, to shepherd their flock, by, in part, praying for each member of the flock (I Pet. 5:1-11).
Third, just as the four marks enumerated in Acts 2:42 imply a fifth, so each mark implies the others such that when one is truly present, the others should be as well (Acts 2:42). By the same token, however, breakdown in one mark entails breakdown in the others as well. Note how, in I Corinthians 11, a defective doctrine regarding communion lead to discord (lack of fellowship) and an absence of self-examination (lack of prayer). Thus, when one mark is absent, we may rightfully question whether the others are really present in the way that Scripture requires.
Fourth, while each of the marks entails the others, no visible church will ever perfectly display each of these marks since the "purest of churches under heaven are subject both to a mixture and error" (Confession, XXV, 5). Contrary to romanticized notions, even the apostolic church saw its share of both truth and error: the visible churches of the apostolic era experienced (a) heresies and doctrinal aberrations (I Cor. 11: 18, 19; Gal. 3, etc.); (b) desecration of communion (I Cor. 11: 20-31); (c) complaints, contentions, and disharmony (Acts 6:1; I Cor. 10, 11; Phil. 4:2); (d) marital disharmony which prevented prayers from being answered (I Pet. 3:7) and prayers without proper coverings (I Cor. 11:5); and (e) lack of discipline resulting in scandalous lives (I Cor. 5).
But just because a church may fall short of perfectly demonstrating these marks doesn't necessarily mean that it's not a true church. Even though the church at Corinth, for instance, fell shorter than perhaps any other church during the apostolic era, nonetheless, Paul still refers to it as a "church" (I Cor. 1:2, 24). God had his remnant in Corinth. Hence, what characterizes true churches from false churches is not visible perfection, but whether such churches adhere to Biblical authority and strive to manifest these marks as much as possible to the glory of God. The visible imperfection of the visible church is no excuse for anyone to withdraw from it altogether, since we are never to forsake the church (Heb. 10:24-25).
I will never know this side of eternity whether Carl was a member of the invisible church. And I will never know what made him forsake the visible church as a whole. But I do know that he woefully failed to understand what Scripture teaches about the church and her Lord.
Make no mistake about it: Carl's understanding of the church was for the dogs!