SITTING on plump cushions in the faux drawing room of a London hotel, Naomi Wolf decides, for some reason, to talk about her epiphany. Wolf, the most widely read feminist of her generation, is fresh from a bruising radio encounter on Woman's Hour with her own heroine, Germaine Greer.

It must have stung to be boxed around the ears by the matriarch icon who once described Wolf 's first book, The Beauty Myth, as the most important feminist tract since her own opus, The Female Eunuch. But Greer, like many other feminists, appears to have cooled towards 43-year-old Wolf since her 1991 polemic against the cosmetics industry radicalised a new generation of women.

Wolf 's follow-up books: Fire With Fire, on career success; Promiscuities, on sexual awakening; and Misconceptions, on marriage and childbirth - developed a feminist treatise from the mirror of her own experiences: what other feminists call an easy life.

Maybe it is an echo of Greer's withering voice that spurs Wolf to open up for the first time in public about her spiritual awakening. Perhaps it is being asked once too often about the hitherto unexplained "mid-life crisis" that caused her to go off, in her early 40s, into the woods of upstate New York to write her latest book, The Treehouse. This self-help meditation on her father's wisdom has drawn accusations that the author is embracing what she used to refer to as "patriarchy".

Or it could have been the conversation about her divorce, during which she stared into the middle distance and seemed to be on the verge of tears. Whatever the reason, the trigger is a simple question about whether all the criticism and bitchiness has hurt her. She pauses then reveals something astonishing: her encounter with Jesus.

Naomi Wolf 's utterances on everything, from childbirth to Al Gore's demeanour, have a disproportionate effect on public opinion. This latest confessional, a self-acknowledged "bombshell", will make a generation of feminists cringe, while for her detractors, it will be the icing on the cake, plunging her into fresh controversy over her beliefs and her integrity as a feminist. Wolf 's very soul is about to become a theological battleground, and she knows it.

"I am not going to be in the closet about this any more. I'm on a spiritual path, I answer to a higher authority, " she says, laughing at the apparent absurdity of the statement. "I don't mean that in a kind of culty way. I'm here on the planet to make change and to help people in the best way that I can. I know what I have to do and if, in the course of doing that, some people get upset, or make fun of me, or attack me, that is not really important in the larger scheme of things."

My next question is more cautious. That higher authority, is it God? "Yeah, God. I believe absolutely that every single one of us is here with a spiritual mission. We come in knowing it and then we forget. If we're lucky, we re-remember. That's part of what this book is about, helping people re-listen to their soul because their soul knows exactly what they're supposed to be doing, even if it is not always clear it knows the direction in which to pull."

She answers everything in a breezy, west coast American way; she can't help herself. Wolf 's life is a series of open books during which she's catalogued everything from her crushing encounters with bulimia to marginalisation in the workplace, the rites of passage of sexual awakening and the invasiveness of the childbirth industry. Hers is a kind of self-centred feminism that turns personal experience into a universal agenda. Often it backfires. When she alleged, 20 years after the event, that she was sexually harassed by eminent academic Harold Bloom at Yale, it did nothing to stop sexist behaviour on campus and everything to open Wolf to further ridicule. Her nemesis, uberfeminist Camille Paglia, sneered that Wolf had been "bobbing her boobs in men's faces" for years. The backlash against her as a feminist lightweight seemed complete.

Today, Wolf seems sharp and incisive. This is no Valley Girl on some psychobabble trip. But when one of the foremost feminists in the world, who is Jewish to boot, says she has met Jesus, the ultimate figure of Christianity and the redeemer of lost souls, it's more than a little disconcerting.

She describes this mystical experience - which happened "a few years ago" - as terrifying, inexplicable and "completely not the appropriate spiritual experience of someone of my background".

Too right. According to Judaism, Jesus is not God made flesh, or a Messianic vision. In a profane world, for anyone of Wolf 's publicly acknowledged intellect to confess to achieving spiritual fulfilment through Jesus is to invite mockery. In her native America, where interfaith rivalry informs all politics, it is a highly volatile admission. Typically of a writer who has spent a lifetime self-dramatising her experiences, Wolf 's epiphany seems to have been of Damascene proportions.

"I was completely dumbfounded but I actually had this vision of . . . of Jesus, and I'm sure it was Jesus." Anticipating a raised eyebrow, she adds quickly: "But it wasn't this crazy theological thing; it was just this figure who was the most perfected human being - full of light and full of love. And completely accessible. Any of us could be like that. There was light coming out of him holographically, simply because he was unclouded. But any of us could become that as human beings."

Although disturbed, she was also elated. "On a mystical level, it was complete joy and happiness and there were tears running down my face. On a conscious level, when I came out of it I was absolutely horrified because I'm Jewish. This was not the thing I'm supposed to have confront me."

Nor does it fit our picture of Wolf as a progressive feminist: the product of a very liberal, San Franciscan upbringing and a privileged education at Yale and Oxford. Although her books have brought her fame and wealth, Wolf 's achievements have always been double-edged. She advised Al Gore's presidential campaign on women's issues but her dollars-15,000 a month wisdom was lampooned by opponents, after she told the vice-president to stop being a beta male and act like an "alpha" president. (Today, she says that her only regret over the matter is that, bound by confidentiality, she couldn't answer her critics at the time. ) She's been repeatedly dismissed as derivative and has borne many vicious attacks from other feminists. As Zoe Heller noted, it stuck in the craw of a lot of women to be lectured about rejecting the Western conventions of beauty by someone who embodied the whole look. Wolf

was, and continues to be, glamorously beautiful, with fresh, open features and thick brown hair.

A decade on from The Beauty Myth, when she seemed at her peak of fame and influence, Wolf 's nuclear family fell apart. Out of respect for the man she still considers an excellent father to her children, she doesn't discuss the split, but somewhere on the road to turning 40 - at a time when she was being acclaimed by Time magazine as one of the most influential voices of her generation - Wolf lost herself.

She realised that for a long time she'd been using her intelligence and her polemical skills at the cost of neglecting her heart and soul. She had her moment of crisis - partly connected with her divorce, but also, it now seems clear, as a result of this unsettling, regressive, religious vision. Then she came through: partly thanks to the eccentric, woolly wisdom of her father, as detailed in The Treehouse, and a spiritual renewal in Jesus.

Born-again Christians might nod in recognition at Wolf 's awakening, but secular society will find it extremely bizarre. At the time, she was struggling with writer's block, and sought help from a specialist, who induced what Wolf calls "a light meditative state", then asked her to walk downstairs in a classic deep relaxation technique. "I opened the door and there he was, " recounts Wolf.

"I wasn't myself in this visual experience, " she continues. "I was a 13-year-old boy sitting next to him [ Jesus] and feeling feelings I'd never felt in my lifetime, of a 13-year-old boy being with an older male who he really loves and admires and loves to be in the presence of. It was probably the most profound experience of my life. I haven't talked about it publicly."

Well, no wonder. She confesses she still feels awkward speaking about it. "It's very embarrassing. We're intellectuals, we're on the left, we're not supposed to talk like that, " she says later.

The experience has made her happier than ever. She's anxious about the repercussions of going public on her life-altering moment, but insists that her commitment to feminism remains as strong as ever. "I don't want to be co-opted as the poster child for any religion or any agenda, " she adds. "There are a lot of people out there just waiting for some little Jewish feminist to cross over. I so much want to distance this from Christianity. It has nothing to do with any religion whatsoever." But in the meantime Wolf has been doing some intensive reading about what the rabbi Jesus had to say, as a Jew "not as this whole Christian construct but as a teacher and a social activist, as a rabbi and as a healer".

Nothing in the folksy, anecdotal style of The Treehouse reveals anything about her religious awakening, but the strength of her conviction is plain. "I absolutely believe in divine providence now, absolutely believe God totally cares about every single one of us intimately, that we're not alone, that we're surrounded by love. That everything is OK."

This avowal, at the end of what could have been just another promotional interview, leaves Wolf slightly shocked. She needs a cigarette, she says, although she quit some time ago. The subject of her next book is intended to be her mother, but this subject, God, seems so much bigger. With her PR at the door, there is just time to ask: will she write about it? She'll have to think about that, she says, disengaging from a conversation she already knows she'll be defending for the rest of her life.

"Let's put it this way. When there's a subject I'm supposed to share with my readers, and this is why I believe in divine providence, I will start getting knocks on the door from the universe. People will start crossing my path saying, 'I'm really struggling with anorexia, I'm struggling with motherhood, I'm struggling with my sexuality.' In the next few weeks if I hear the call that this is something I should bring forward, then I'll bring it forward more. But I've just taken a huge step, so give me credit. Let me get over that."

It's as if she's said too much. She leaves the room in a hurry.

The Treehouse is published by Virago, pounds-12.99