To many of us, the specter of so much control suggests the possibility, even the inevitability, of rebellion. The Scheibners' oldest children are 12 and 11. What happens when they hit their teen years? Won't their hermetically sealed world spring a leak? Generational self-definition is a dearly held precept in our culture, which is why it seems to make sense to us that both Megan and Steve come from religiously indifferent families in which they defiantly distinguished themselves by their theological conservatism.

When you ask the Scheibners to imagine the future for their own kids, though, they can't picture them going astray. Peter has wanted to be a missionary for the longest time now, and since he and his parents regard this as something he has been called to do, they entertain few doubts about his doing it. Admittedly, it's hard to imagine Peter as a renegade. He is the kind of kid who, when asked in all innocence whether he ever listens furtively to his beloved ''Lord of the Rings'' tape in bed, looks shocked and says, ''Oh, no, when it's time to go to bed, it's time to go to bed.'' He loves being home-schooled, and not long ago took it upon himself to write a letter to Senator Rick Santorum of Pennsylvania. It read, in part, ''I have the joy of knowing I am going to heaven because when I was 4, I asked Jesus to come into my heart and save me from sin.''

After spending some time with the Scheibner family, I was not particularly surprised to learn that evangelical Christians have one of the highest intergenerational retention rates of any major religion -- meaning that, as Christian Smith puts it, ''they have a great ability to raise children who do not become theologically liberal or nonreligious when they grow up.'' Certainly they work extremely hard to prevent what they see as the tragedy of apostasy. And the new availability of Christian media and of home-school curriculums helps enormously. A generation ago, evangelical families who wanted to shield their children from mainstream culture had little to replace it with, other than self-denial. Now they can offer goodies of their own. And new companies and institutions are springing up all the time to meet their needs. The Scheibners, for instance, are very excited about the founding of the first college primarily for Christian home-schoolers, Patrick Henry, in Purcelleville, Va., which will be accepting its inaugural class of students in the fall. Among other things, Patrick Henry will ask its students to sign a pledge in which they promise to court and not date.

And after college? Neither Megan nor Steve is outright opposed to their daughters' working, especially before they have children. Like many conservative Christians, they warm to the idea of a wife running her own little business from the home. ''Proverbs 31 talks about the woman who made purple linens at home and sold them,'' Steve points out. But they warm even more to the idea of their daughters ''having an eye to serve without compensation,'' as Megan says. They think too many working women have forgotten the virtues of volunteerism. And if one of their girls was to pursue a full-fledged career, Steve says, ''we'd still love her and encourage her and, after all, at some point it's her life,'' but they would also find it hard to disguise their disappointment. ''A career takes away from what I think their primary happiness will be, which is being a good mother,'' Steve says.

And then he gives a little speech that bears the distinctive hallmarks of the new Christian counterculture. ''You know,'' he says, ''you may have lots of pats on the back at work, you may have a successful career and a lot of money and great cars to drive, but in the end it always lets you down. Look at any number of gazillionaires out there -- men, women, it doesn't make any difference -- who have awful, tragic lives. Those things are not the things that satisfy. The things that satisfy are raising a good family, having love.''

America has a long history of separatist movements, and within that history, there are, to put it bluntly, the bad separatists and the good ones. In the former category are the stockpilers of guns, the people who don't pay taxes or vaccinate their children -- people who lack any sense of their duty as citizens. And in the latter category are people like the Scheibners. Indeed you could argue that their sort of separatism is good for the culture at large -- or at least represents a reasonable compromise. If they are committed to teaching Creationism, for example, better that they teach it at home than insist that the public schools do. Besides, a culture that lacks a thriving and reproving counterculture is always in trouble. The very existence of alternative ways of life like the Scheibners' keeps alive a debate about the role of morality and religion in our culture and politics that probably ought never be declared over and done.

And yet you have to wonder about a way of life that requires such rigorous policing of its psychic boundaries. There is something poignant, for a parent like me anyway, about the idea of sons and daughters who love you as uncomplicatedly in their teenage years as they do when they were small -- who are, indeed, your best friends -- but there is something unreal about it too. There is something inspiring about the prospect of an American childhood in which advertising does not invade the imagination so relentlessly, but something claustrophobic about the notion that the only alternative is a sequestered family life. There is something fundamentally right and useful about the argument that American culture promotes independence at the expense, often, of the more nurturing virtues, but something sad and scared about the idea that the safest solution to this is early marriage. If the Scheibner philosophy allows girls to linger longer at the threshold of adolescence -- not having to worry about being thin or sexy -- it also pushes them much earlier into wifely domesticity.

By next summer, the Scheibners will be living in Maine, and they are looking forward to the move. Steve is eager to ''plant'' his new church. Megan thinks ''the slower pace of life'' there will make it that much easier to shelter the children from evil. The younger kids are excited about going crabbing and maybe seeing a moose or two on the rambling, wooded acreage where their new house will be. Katie, the oldest, is excited, too. She says she's hoping to find ''a little place of my own, where I could read or think, and nobody would know about it.''