Because this is the most contested subject in intra-ecclesial apologetics, it should be handled with the most care. The claim is a narrow one. It says that the New Testament's texts on financial support fit four identifiable categories, that every support text can be placed in one of them, and that the arrangement most churches now run (a settled, salaried, professional pastor of a local congregation) isn't in any of the four. It doesn't say that paying anyone is sinful.
Category one: the settled elder who works
Paul's farewell to the Ephesian elders is the clearest statement of what a local elder's relationship to money looked like:
I have coveted no man's silver, or gold, or apparel. Yea, ye yourselves know, that these hands have ministered unto my necessities, and to them that were with me. I have shewed you all things, how that so labouring ye ought to support the weak, and to remember the words of the Lord Jesus, how he said, It is more blessed to give than to receive. (Acts 20:33-35)
These hands have ministered unto my necessities. Paul worked. Then he adds I have shewed you all things, how that so labouring ye ought to support the weak. He's telling elders that his working was an example for them, and that they, too, should labor with their hands so as to be givers rather than receivers. The local elder in Paul's model earns his living and gives.
Peter's instruction points the same way: Feed the flock of God which is among you, taking the oversight thereof, not by constraint, but willingly; not for filthy lucre, but of a ready mind (1 Peter 5:2). The qualification lists require that an elder be not greedy of filthy lucre (1 Timothy 3:3; Titus 1:7) and one that ruleth well his own house (1 Timothy 3:4). That describes a man with a household and a livelihood, known in the community.
Category two: the itinerant who may be supported
The second category is the traveling worker (the apostle, the evangelist sent out), and here the New Testament explicitly permits support:
Even so hath the Lord ordained that they which preach the gospel should live of the gospel. (1 Corinthians 9:14)
As the strongest text for supporting Christian workers, it must be given its full weight. But the whole chapter is about apostolic rights. Paul asks, Have we not power to eat and to drink? Have we not power to lead about a sister, a wife, as well as other apostles? (9:4-5). The right belongs to those sent, since the word apostle means sent one. And the provenance of the ordinance is Jesus's sending discourse: the labourer is worthy of his hire (Luke 10:7), said to the seventy as he sent them out two by two, town to town, with no bag and no purse.
And then Paul declines the right: But I have used none of these things... What is my reward then? Verily that, when I preach the gospel, I may make the gospel of Christ without charge (9:15, 18). The itinerant may be supported. Paul's own practice was to be supported by churches he wasn't currently with (I robbed other churches, taking wages of them, to do you service, 2 Corinthians 11:8; Philippians 4:15-16) and to work when he was present.
Category three: the dependent who must be supported
The third category is the person who can't provide for themselves, and here the church's obligation is absolute:
Honour widows that are widows indeed... If any man or woman that believeth have widows, let them relieve them, and let not the church be charged; that it may relieve them that are widows indeed. (1 Timothy 5:3, 16)
All of 1 Timothy 5 is an allocation policy for the church's fund: who qualifies, who doesn't, in what order, so that the fund reaches those who have no other source. Honour in verse 3 means material provision. It's the same honour as the fifth commandment, and Jesus condemned the Corban rule exactly because it let a man withhold provision from his parents under a religious pretext (Mark 7:10-13). To honour is to provide.
Category four: family mutuality
The fourth category is the ordinary sharing of a household:
Let him that is taught in the word communicate unto him that teacheth in all good things. (Galatians 6:6)
Communicate is koinoneito, meaning to share or to have in common. The taught share good things with the teacher. This is koinonia, the mutuality of a family, in which the one who receives teaching also receives an obligation to share hospitality, provision and care. Nobody in it draws a salary.
Every text placed
Run every support text through the four. Acts 20 falls in category one. Category two holds 1 Corinthians 9, Luke 10, Matthew 10, Philippians 4 and 2 Corinthians 11. In category three go 1 Timothy 5:3-16, Acts 6:1 and James 1:27, and Galatians 6:6 goes in category four along with the general commands to hospitality.
No fifth category appears anywhere, in which a settled elder of a local congregation draws a salary from that congregation as his livelihood, on a permanent basis. The New Testament has working elders, supported itinerants, provided-for dependents, and family mutuality, but no professional pastorate.
The earliest Christian document outside the New Testament that deals with this is the Didache, from around the end of the first century. It is honest counter-evidence, because it permits settled prophets and teachers to receive first-fruits. So the arrangement was emerging early. But it was only emerging, in a document that also warns repeatedly against those who ask for money. The apostolic texts don't contain it.
The weakest joint, named
An airtight argument names where it's most exposed. This one is most exposed at 1 Timothy 5:17-18:
Let the elders that rule well be counted worthy of double honour, especially they who labour in the word and doctrine. For the scripture saith, Thou shalt not muzzle the ox that treadeth out the corn. And, The labourer is worthy of his reward.
The majority of commentators read double honour as financial support for teaching elders, for reasons that aren't foolish. The verse is followed by a quotation about wages. The word honour has just meant material provision for widows. And especially they who labour in the word naturally sounds like the labor is what the support is for.
The reply comes from the frame. The chapter is an allocation policy for dependents, widows first and then elders who have devoted themselves to teaching, and verse 17 stands inside it. Elders who rule well and have given themselves to the word may be provided for from the fund, as widows are. That reply is strong. It isn't decisive, so don't present it as decisive.
The alternative reading, followed through, produces a settled teacher supported from the dependents' fund, which is category three or a modest extension of it. It doesn't produce a professional pastorate with a salary set by market rate and a contract. Even on the majority reading, the taxonomy holds.
Why the working elder is the design
Set the exegesis aside and ask what the working elder does that the salaried pastor can't.
He's one of the members, in the same economy, with the same pressures. People imitate a leader like that instead of admiring him from a distance. He can't be captured by the congregation's money, because he doesn't depend on it; he can say the hard thing on Sunday because the mortgage doesn't depend on Monday's reaction. He demonstrates that the Christian life is lived in ordinary work and needs no religious profession. He's present in the community all week, in the places members are. And working elders multiply. A congregation can have five of them for the cost of zero salaries, where it can afford one professional.
There's also a well-documented finding about what payment does to motivation. Attaching money to something people did freely can shift the reason they do it, and the shift is often irreversible. Remove the payment and the free version doesn't come back. Whether that applies to eldership is a fair question. But the design's caution about filthy lucre looks, on that evidence, less like scruple and more like foresight.
The transition problem
None of this licenses a congregation to cut its pastor's salary next month. Real people have built real lives around the current arrangement in good faith. A reform that requires somebody's family to absorb the cost of your conviction is an expense you have assigned to someone else. Any move toward working eldership must be gradual and honest. Its cost belongs to the people who want it, and the man who was hired under the old rules shouldn't bear it.
But the direction is clear, and the argument for it is the New Testament's own. Every text has its place in one of four categories. The fifth arrangement, now universal, is one the apostles who wrote the letters wouldn't have recognized as theirs.