There's one Greek word that, more than any other, settles what kind of thing the church is. It is allelon — "one another." It appears about a hundred times in the New Testament, and in the epistles it's attached to a command nearly sixty times.
Love one another (John 13:34). Be kindly affectioned one to another (Romans 12:10). Receive ye one another (Romans 15:7). Admonish one another (Romans 15:14). Serve one another (Galatians 5:13). Bear ye one another's burdens (Galatians 6:2). Forbearing one another, forgiving one another (Colossians 3:13). Comfort one another (1 Thessalonians 4:18). Exhort one another daily (Hebrews 3:13). Consider one another to provoke unto love and to good works (Hebrews 10:24). Confess your faults one to another, and pray one for another (James 5:16). Use hospitality one to another (1 Peter 4:9). Minister the gift one to another (1 Peter 4:10). Be subject one to another (1 Peter 5:5).
Read that list slowly, and notice something grammatical: every one of those is a reciprocal verb. The action runs in both directions at once. I bear your burden; you bear mine. I confess to you; you confess to me. I admonish you; you admonish me.
There's no professional form of a reciprocal verb.
What the grammar rules out
A professional can teach a congregation. A professional can pray for a congregation. A professional can counsel a congregation, one at a time. What a professional can't do is one-another a congregation, because the verb has no one-way form. The moment care flows from a single source to many recipients, it has stopped being the thing the text commands and become something else — something good, perhaps, but not this.
That isn't a criticism of pastors. It's a description of grammar. The commands were written to the brethren — the members — and they describe what the members do to each other. A church in which the members are recipients and the leadership is the sole agent hasn't failed to obey the one-anothers well. It has arranged itself so that the one-anothers can't be obeyed at all.
Paul makes the point explicit in Ephesians 4. The gifted leaders — apostles, prophets, evangelists, pastors, teachers — are given for the perfecting of the saints, for the work of the ministry, for the edifying of the body of Christ (4:12). The leaders equip; the saints minister; the body is built. And then the mechanism:
From whom the whole body fitly joined together and compacted by that which every joint supplieth, according to the effectual working in the measure of every part, maketh increase of the body unto the edifying of itself in love. (Ephesians 4:16)
Every joint. Every part. The body builds itself, and the building is done by the working of each member. A body in which one part does all the working isn't being built. It's being carried.
Why the commands need a form
Ask a practical question. Where, in the week of an ordinary church member, could these commands be obeyed?
Confess your faults one to another requires a setting where confession is safe: small, trusted, unhurried, with people who will still be there next week. Bear ye one another's burdens requires that I know your burdens, which requires that you have told me, which requires proximity and time. Exhort one another daily — daily — requires that we see each other more than weekly. Use hospitality one to another requires a table and a home. Admonish one another requires that we know each other well enough to see what needs admonishing, and love each other enough to survive it.
Not one of these can be obeyed by an audience facing a platform for ninety minutes on Sunday. The form of the modern service doesn't merely fail to encourage the one-anothers; it makes them structurally unavailable. A member could attend faithfully for forty years and never once be in a room where confess your faults one to another was possible.
This is why the early church looked the way it did. Breaking bread from house to house (Acts 2:46). The church that is in their house (Romans 16:5; 1 Corinthians 16:19; Colossians 4:15; Philemon 2). When ye come together... every one of you (1 Corinthians 14:26). The house wasn't a preference. It was the form in which sixty reciprocal verbs could be done.
The commands are a system
Here's something that becomes visible only when you lay the one-anothers side by side: they interlock.
Confession (James 5:16) requires safety. Safety is produced by the honour inversion — upon these we bestow more abundant honour (1 Corinthians 12:23) — and by forbearing one another in love (Ephesians 4:2). Correction (Galatians 6:1) is survivable only where forgiveness is habitual (Colossians 3:13). Burden-bearing (Galatians 6:2) requires the hospitality that puts people in each other's homes (1 Peter 4:9). Mutual teaching (Colossians 3:16) requires a gathering small enough that all may learn (1 Corinthians 14:31).
Remove one and the others weaken. Adopt one without the rest and it fails predictably. A church that adds "small groups" but keeps the platform as the only source of teaching gets groups that share prayer requests and never confess. A church that adds confession without safety gets wounded people. The commands were given together because they work together.
That's what the New Testament means by a body. Not a metaphor for warmth. A description of interdependent function.
The objection: isn't this too demanding?
Some will say: this is beautiful but impossible. Ordinary Christians are busy, tired, and not trained. You can't expect a plumber to admonish and a nurse to teach.
The objection has the design backwards. The one-anothers aren't written to trained people. They're written to the brethren — to everyone, including the plumber and the nurse. Hebrews rebukes believers exactly for not having become able:
For when for the time ye ought to be teachers, ye have need that one teach you again which be the first principles of the oracles of God. (Hebrews 5:12)
Ye ought to be teachers. The expectation is that ordinary members grow into the reciprocal verbs. And they grow into them the only way anyone grows into anything: by doing them, badly at first, alongside people who do them better. The one-anothers aren't a standard for the mature. They're the training that produces the mature.
The real obstacle isn't that people are too busy or too untrained. It's that the room has been arranged so that they never get the chance.
What to do this week
Take one verb. Not ten — one. Confess your faults one to another or bear ye one another's burdens or exhort one another daily.
Find one other believer. Sit at a table. Do the verb.
You will find it awkward. You will find you have no practice. You will find that nineteen years of church have prepared you to receive and not to give. And you will find, at the end of an hour, that you have obeyed a command of Scripture for the first time — and that it wasn't too demanding after all. It was simply never available.
Then do it again next week. That isn't a program. It's the church, in seed, doing what the grammar requires.