Sociologist Rodney Stark used to be a reporter for the Denver Post. Several years ago he was in a motel in a Wyoming town, covering a murder trial that lasted four days. Finding himself with a lot of time on his hands, he pulled a Gideon Bible and a Book of Mormon out of the drawer.

"I had never seen a Book of Mormon before," says Stark. "So I sampled it. I probably spent four or five hours over a couple of nights reading it. I remember saying, `Well, what's so controversial? There's nothing here for anyone to object to!' "Later, Stark jumped from journalism to the academic world. Now an eminent professor of sociology and comparative religion at the University of Washington, he is famous for using sociological theory for studying American religious history.

Through such notable books as "The Churching of America," and "The Rise of Christianity," he has become famous among students of religion.

This year he was invited to be the non-Mormon scholar to deliver the annual Tanner Lecture about Mormonism at the recent meeting of the Mormon History Association in Washington, D.C.

Prior to the lecture, Stark spoke candidly about what he regards as the prestigious place of Mormonism in American religious history.

Although he bemoans the lack of data on the rise of Christianity, he can hardly imagine any better historical data "on any movement at any time in history than there is on the history of the Mormon Church."

Through research in Mormon family history, Stark has isolated 28,000 people who joined the church from 1830 until 1848. "It's astonishing that we have that. It's one great, huge, interlocking kinship network. Everybody was cousins of everybody else, and by marriage into the next set of cousins."

Stark is excited about the "breathtaking kinds of things" he has been able to do with this information, including building models that "fit everywhere."

For instance, when Samuel Smith met Phinehas Young in Mendon, N.Y., in April 1830, he gave him a copy of the Book of Mormon. Young had heard about it from his sister, Rhoda, and her husband, John Greene.

Young studied it, then loaned it to his father, Joseph Young, who was so impressed that he handed it to his sister, Fanny. In spite of this doctrinal introduction, says Stark, it required two more years of interacting with committed Mormons before the Youngs were converted.

"Then, in April of 1832," says Stark, "John Young and his wife, Hannah, four sons, three daughters-in-law, two daughters and two sons-in-law were baptized as Mormons. A month later, two more of Joseph Young's daughters and their husbands were baptized. The next year another Young son, daughter and son-in-law were baptized. By building strong friendship ties to several members of one family, the Mormons gained 20 converts including Brigham Young!"

Beginning 18 years ago, Stark made straight-line projections of Mormon growth. Today he says the church is well ahead of his most optimistic projection.

"Is the church going to have 267 million members in 2080? I have no idea. But I'll tell you - 20 years ago, people certainly would have scoffed at the idea that it would number 10 million in 1998."

Stark believes Mormonism is "potentially a new world faith," comparable to that developed by Mohammad in the eighth century.

Seeing similarities between Joseph Smith and Mohammad, Stark said that in both the Book of Mormon and the Koran, witnesses reported that Smith and Muhammad "appeared to be reading or hearing the text, not composing it - there were not a lot of false starts and long pauses as would be expected had the revelator been making it up as he went."

Stark has studied Mormon missionary work and found that when "knocking on doors cold," one in a thousand leads to a new church member. But, if the missionaries have their first contact in the home of a close friend or relative of the potential convert - 50 percent of the people join the church.

"That means," claims Stark, "that missionaries have a role to play, but the backbone of conversion is the rank and file bringing their close friends and relatives into the church they've already joined."

Stark adds, "Just because I join the church doesn't mean I know one darned thing about being a Mormon. Now I've got to learn what it is I've joined. I've got to learn the hymns, the history, the traditions, the scripture - and one of the problems in these rapidly growing areas is that you have whole wards full of people who have only been in the church about nine minutes."

The significance of networking in conversion may explain why Southern Baptists were unable to fill their nets with Mormon converts in their recent fishing expedition in Salt Lake City.

"When they step out of theology, Mormons and Baptists have a lot in common, such as family values and decency," says Stark.

Stark has been surprised to find "hard-line particularism among scholars of religion."

He has always been "astonished at the extent to which colleagues who would never utter an anti-Semitic or anti-Catholic or even anti-Muslim remark, unself-consciously and self-righteously condemn Mormons. It is time we did better."

Although Southern Baptists criticize Mormons for their interpretation of God, Stark compliments them: "Latter-day Saints do not mean merely to worship God . . . They mean to become divine. LDS theology maintains that each person is expected to achieve sinlessness. The process may take several million years of posthumous effort, but there's no reason not to get started on the job right now."

In his Tanner lecture, Stark said that "When an individual's attachments to a member or members of another religion outweigh his or her attachments to non-members, conversion will take place."

That has not yet happened to him, although Armand Mauss, Mormon History Association president, jokes that Stark "has sometimes been suspected of being `a closet Mormon,' because he is an enthusiastic friend of Mormon studies and of Mormon people."

One thing is sure. Stark's research has set the agenda for the sociology of religion well into the next century - and the Mormon faith plays a dominant role.