Many people in alternative worship have been playing around with the donut joke for a while now. Alternative worship groups, it is said, are like ring donuts - lots of tasty stuff around an empty centre. This is because many groups generate impressive appearances, products and reputations, while very few people attend the actual events. The problem with the analogy is that there are people in the 'empty' centre, generating the donut. In fact the donut is more like a lifebelt, keeping them afloat.

The problem of the donut is numbers - the 'empty' centre - rather than product, which the analogy agrees is tasty enough. Even those in alternative worship are still prone to judge worth by attendance. It's not that any of us, in our heart of hearts, measures spiritual success that way. But the missionary, nay evangelistic parts of ourselves want to be as popular as possible, want to touch as many as we can, want to see them return, bringing their friends and neighbours. Want to give our critics a bloody nose.

The strange thing is, people praise alternative worship in theory while still dragging themselves along to conventional churches in practice, complaining that they're bored. What's at issue here is effort, as much as anything else. We are consumers in our spiritual lives as in the rest. The churches that are growing are usually big already, big enough to offer everything ready-made, big enough to offer reassurance that we have made the right choice. And another food analogy suggests itself, from our shopping habits.

Supermarkets offer size, convenience, variety - you need never go elsewhere. They have efficiencies of scale. Your experience of ease and simplicity is assured by large teams of staff, many in back rooms, and all backed up by by systems and networks designed to deliver what you want, when and where you want it without you ever noticing the effort or cost. Supermarkets provide so much variety that the things you cannot, in fact, buy seem marginal or unimportant. You are encouraged to focus on the choice you have, rather than worry about the one or two things you cannot have - even if in another less dazzling context they might stand out as the most essential needs. Supermarkets offer a universe which claims completeness.

Once nearly all shops were 'cornershops' - small, independent, local. But small, independent, local has its costs. There are no economies of scale. Things cost more. It's not possible to provide everything. A few staff do everything, all the time. Cornershops struggle to survive in a world whose retail systems are controlled by supermarket chains. In fact many cornershops have joined themselves into chains in order to be players in those systems. Once upon a time cornershops provided inescapably personal service. You probably had to ask for things to be got down from shelves or weighed. Nowadays most cornershops mimic supermarkets. You serve yourself from the prepackaged goods, mutter something to the assistant and are gone.

And most of us prefer it that way. We have made decisions about values. We prefer cheapness, speed, lack of involvement. We prefer that difficult choices have been made for us, the vegetables scrubbed and chopped, the results guaranteed. We like to fill up the car and not go back too often.

Those who prefer cornershops seem stuck-in-the-muds, or swimmers against the tide. When they talk of personal service, of locally produced goods, of community, we agree that these are nice things. Maybe we'll pop into our local cornershop occasionally to try them out and feel good. But we won't alter our underlying shopping habits. Of course, if we all went to cornershops the food retail system would be turned on its head, with who knows what results. But most people will continue to do what most people continue to do, because most people do it. We're not sure that we want to be different.

Big churches offer reassurance, which matters greatly when Christianity is unfashionable. If lots of other people are doing this it must be a good choice. If people seem attractive and successful we're reassured that we won't end up sad and strange on this path. If the teaching is clear and authoritative we accept it, especially as so many other people agree with it and can tell you how it did them good. Big churches are like big brand food. You know what you're getting, that experts have guaranteed it safe and nutritious. You know that it says you're normal not cranky or weird.

Alternative worship offers few such assurances for the novice. There aren't many people here. It's not the normal way things are done in church. It's not clear what you are expected to believe or how you are expected to behave. Supposing it's not right? Not that I can see anything wrong exactly, but how can I be sure there isn't something hidden that I wouldn't know about? Where's the big name guarantee? Have the church leaders approved this? We read the small print on the packet, anxiously.

It's possible that alternative worship would grow better if it were more like a denomination. A clear consistent product, reproducible and reassuring. Well-known qualified leaders, a central organisation. Doctrinal guidelines, checks and balances. Like the cornershops that have turned themselves into mini-supermarket chains. Success by capitulation to the dominant culture. Some people worry that alternative worship accepts contemporary culture too uncritically, enjoys its products and methods too well. But there is another level of co-option, the systemic level where we become another brand of church as it is already known. When it's at that level that we most need to be countercultural, even at the cost of never being successful. God demands no less.