One of the most entertaining chapters in Jeff Sharlet's book, "The Family," comes about halfway through and is titled "The Blob."

The chapter describes a propitious meeting between a screenwriter and an evangelical filmmaker that led to the making of the 1958 B-movie "The Blob," about gooey stuff that oozes out of drains and eats people - a metaphor for, in Sharlet's words, "the creeping horrors of communism."

But the blob also becomes a metaphor in Sharlet's book for his subject, the fundamentalist Christian group the Family, secretive but ubiquitous, recruiting powerful people in business and politics across the country and the world.

The Family is slippery - its methods personal, its influence subtle - but, through an exploration of its historical roots and vivid contemporary anecdotes, Sharlet shows the vast influence of what the Family's founder, Abram Vereide, calls "the Idea."

The Idea is slippery, too. It is not grounded in the specific dictates of Scripture, such as ministering to the poor. It is more a mood than a mission - the mood of the true believer, whose only duty is to believe.

The Family seeks to sign on "top men" wherever it can, even if those men are amoral dictators like Indonesia's Suharto, corrupt to his core and responsible for mass killings of innocent people. Suharto was a Muslim, but, because he was willing to break bread with members of the Family and join its web of "top men," the group embraced him.

The dark side of the Family, spelled out by Sharlet in many examples spanning decades, is the cover it gives to bad behavior, justifying in Christ's name silence about the most un-Christian acts imaginable.

The Family spreads its Idea personally, through the "man-method," one intimate persuasion after another. Responsibility, however, is seen as anything but personal. Jesus Christ is in charge, human beings are puppets in his command and God's will can be invoked to escape any responsibility for befriending monsters, or failing to protest massacres.

Sharlet's own family has roots in Glens Falls ,and one of the book projects he is hoping to do soon involves his father's brother, who launched a GI war resistance movement following a stint in Army

intelligence during the Vietnam War.

First, though, Sharlet is working on a book more closely tied to "The Family," about fundamentalism in the U.S. military.

Sharlet has lived in New York, teaching at New York University, and in Rochester, and now lives in Cambridge, Mass. His wife teaches at Boston University.

"She's a real academic," Sharlet said. "I'm a fake academic."

But one of the pleasures of "The Family" is Sharlet's willingness to approach his subject in various ways besides the journalistic, including historical and academic.

Much of the first half of the book is spent tracing the roots of American Christian fundamentalism, from Jonathan Edwards, the Massachusetts preacher who, in the earlier 1700s, led the Great Awakening; through Charles Grandison Finney in Western New York a century later; to Vereide, a Norwegian who immigrated to the United States early in the 20th century and came to the conclusion that the best way to spread the word of God was through the world's "big men."

Woven through the second half of the book, among the revelations about the Family's far-flung influence, are Sharlet's musings about and questionings of the moral and spiritual content of the group's activities.

A character in the book himself - Sharlet lived for a time in a Family retreat in Washington, D.C. - Sharlet manages to be both fair and judgmental about the organization and its followers.

More than anything, in the course of revealing the contours of what had been a largely unknown group, Sharlet raises questions - about the role of religion in American politics, about ethics in faith, about right vs. might.

Although appalled at times by the lack of concern among people affiliated with the Family about end results - all that matters is the Christian spirit - Sharlet doesn't attack, he questions.

His approach is fitting since, in the book's conclusion, he suggests a questioning stance as the counterpoint to what could be the worst aspect of American fundamentalism, its certainty about the order of the universe and emphasis on acceptance - what Sharlet calls its "numbing authority."