I updated this article on 21 February 2021.
Emil Brunner suggests the church catholic is not properly an external institution or organization at all, but “a brotherhood resulting from faith in Christ.” He sees the visible church is only the shell or instrument of this brotherhood. So, the thinking goes, when we think of “the church,” we shouldn’t think,
Well, in a church you have the pastors, the deacons, and Christians who join the church. And, the whole Church is the collection of these individual churches.
That’s a corporate view; you look at God’s community as one big organizational chart with branches and sub-boxes for different denominations. This isn’t necessarily incorrect if you squint a certain way, but perhaps it’s not good enough. The Church, Brunner notes, is a brotherhood of all who have faith in Christ. It’s a far-flung family knit together by a love for one another that reflects God’s love.
Brunner is somewhat difficult to follow as he discusses his conception of the Church “as a spiritual brotherhood which is not an institution.” At some point, one has to come out of the abstract clouds and function in the minutiae of real life. But, his emphasis on “brotherhood” as the distinguishing mark of the Church is intriguing. And, I daresay many Christians do employ an “organizational” lens as they consider the nature of God’s New Covenant arrangement for His people.
What’s the mark of a true church? Christians have written about this for a long time, including me. But, again, these answers often seek to answer an organizational question. They implicitly address the query, “what pieces must be in place for a ‘church’ to exist?” So, you have answers like, “a true church has apostolic doctrine, is holy, is one, and is catholic (that is, universal).” It’s rarer for a definition to address what the Church actually is. In that respect, Brunner is on to something.
So, carrying on the image of the Church as a brotherhood or family knit together by shared faith in Jesus Christ, why don’t we think of brotherly love as a defining mark of the redeemed community (1 Jn 4:19-21)?
John on brotherly love
John would not truck with antinomianism of any sort. He believed there must be fruit as a mark of salvation. One key fruit is brotherly love. If you do not love your brother, you are a child of the devil (1 Jn 3:10). This has been God’s message from the beginning; from the very beginning.“We know that we have passed out of death into life, because we love the brothers,” (1 Jn 3:14). If you do not love the brothers, you abide in death and are a murderer, like Cain (1 Jn 3:14-15).
Of course, Jesus is the model. He sacrificed Himself for His people, so Christians must have the same sort of love (1 Jn 3:16). This means brotherly love cannot be earned or deserved; it must simply be given … because this is what God does in salvation. This is a hard saying.
Add to it, this love must be demonstrated (1 Jn 3:18). Talk is cheap. Assurance of salvation hinges on that; on whether you demonstrate brotherly love (1 Jn 3:19). John reminds us God’s commandment is that “we believe in the name of his Son Jesus Christ and love one another,” (1 Jn 3:23). He echoes Jesus (cp. Mk 12:28-34) by collapsing two commandments into one. There is a perichoresis; a necessary correlation of ethics between these two commands. The one who obeys His commandments (that is, the summary from 3:23) remains in union with Christ, and Christ with Him (1 Jn 3:24).
John, eager to emphasize this point, explains that brotherly love only happens because of covenant membership; because someone “has been born of God, and knows God,” (1 Jn 4:7). “Anyone who does not love does not know God,” (1 Jn 4:8). If you do not love your covenant brother, you are lying about being a Christian (1 Jn 4:20).
Why? Because of the imago dei. “Because God is love,” (1 Jn 4:8) in a metaphysical sense, so regeneration and covenant membership mean a restoration of that image. God is love because of the community of the Trinity; so, Christians must model that community in the family of God. Like Paul before him, John points to Christ as the example (1 Jn 4:9-10). His love is unearned and undeserved (1 Jn 4:10), thus “if God so loved us, we also ought to love one another,” (1 Jn 4:11). We must love our brothers and sisters even when they do not “deserve” that consideration.
Christians have never seen God but, through the vehicle of brotherly love, John hints we can experience His indwelling presence more fully (1 Jn 4:12). Thereby “[H]is love is perfected in us,” (1 Jn 4:12); meaning the more we love one another, the more we model His kind of love in our lives and so image the imago dei on earth.
When this brotherly love is missing, God is most angry and disappointed (Jer 9:4-9; 1 Jn 5:1). Our brotherly love should reflect the intra-trinitarian, perichoretic love of Father, Son and Spirit (1 Jn 4:8). It is that love that binds them as One.
Back to Brunner
So, in a true “church family,” this love pushes outward, impelling the congregation to reach out to the world in love to offer them reconciliation, love and peace. It’s this love that moves us to evangelize, and it’s this same love that shows us as genuine to the lost. As Brunner has written, “[a] man is laid hold of by the life of the fellowship, moved by the love he experiences there; he ‘grows into’ the brotherhood, and only gradually learns to know Jesus Christ as the Church’s one foundation.
To a cynical reader, Brunner may sound like a proto-Bill Hybels. This is incorrect. Rather, his point is that a community formed by faith in Christ, marked by love, influenced and energized by the Spirit, will be blessed by God. “[T]hrough receiving human love he comes to believe in Him from whom this love originates.” Salvation primarily comes by confrontation with the gospel, but it can come by this second way. The Church, Brunner observes, has historically not reckoned with this second way which leads the sinner to Christ through fellowship.
Each of us reflects the theological milieu of our times. I suspect Brunner, in his distaste of rote doctrine and institutionalized churches, is reacting against the cold, frigid State churches of continental Europe in the mid-20th century. Perhaps I’m wrong. But, his emphasis on “church as brotherhood” is profound. The Church does not simply “know” God is love. It is immersed and energized by that love. “The Spirit who is active in the Ekklesia expresses Himself in active love of the brethren and in the creation of brotherhood, of true fellowship.”
The one thing, the message of Christ, must have the other thing, love, as its commentary. Only then can it be understood and move people’s hearts. True, the decisive thing is the Word of witness to what God has done. But this Word of witness does not aim merely to teach, but also to move the heart.
A family that hates is not a functioning family. Likewise, a congregation that does not love one another is a dead church. There are other good marks of a true church. But, brotherly love must certainly be one of them.
 Emil Brunner, The Christian Doctrine of the Church, Faith, and the Consummation, Dogmatics vol. 3, trans. David Cairns (Philadelphia: Westminster, 1960), p. 128.
 Ibid, p. 129.
 Ibid, p. 128.
 The immediate context of 1 John 3:11 suggests the beginning of the Gospel, but the principle goes back to the very beginning of creation. John’s reference to Cain supports this interpretation (1 Jn 3:12). After all, Jesus did not create the ethos of brotherly love for the New Covenant.
 This is my own translation.
 “… when we love others, God’s love for us has reached its full effect in creating the same kind of love as his in us,” (I. Howard Marshall, The Epistles of John, in NICNT [Grand Rapids: Eerdmans, 1978; Kindle ed.], KL 3672 – 3689.
 Brunner, Church, Faith and Consummation, p. 136.
 Ibid, p. 134.
 Ibid, p. 136.