DERYL DAVIS: Looking at Quakers in silent meeting today, you'd never know they got their name because early adherents were said to quake with zeal during worship.

Mostly now, they're contemplative -- listening in silence for the voice of God. Occasionally, they're moved to share the experience.

Unidentified Woman: God is surely present in me, as surely as God is present in all of you.

Quakers have always combined their quiet listening for God's guidance with active work in the world, especially peacemaking.

In the past century alone, they have helped start nearly 200 social service, environmental, and relief agencies such as the American Friends Service Committee. And, they are the only religious organization to win the Nobel Peace Prize.

But, in spite of its many achievements, almost 350 years after its founding, the Religious Society of Friends -- as Quakers are formally known -- remains small in numbers.

There are fewer than 120,000 members, or Friends, in the U.S. today. Not many more than 150 years ago.

Douglas Bennett, President of Earlham College and Earlham School of Religion, recently oversaw a major study of Quaker life in America.

DOUGLAS BENNETT (President, Earlham College and Earlham School of Religion): There certainly are some Friends who are worried about Quakerism disappearing altogether. That our numbers may become so small that we disappear from the landscape.

Unidentified Man: Can we puzzle through that?

DAVIS: Why aren't there more Quakers? First, Quakers don't have a specific structure for handing the faith down to their children.

SALLY RICKERMAN (Philadelphia Outreach Committee): We teach Quakerism by osmosis, and osmosis does not always permeate from one body to the next.

DAVIS: And it's a difficult faith to live. Quaker ideals go against the grain of much in modern culture.

Generally, they don't fight in wars, refuse to swear oaths, are active in civil rights and peace movements, and live very simply.

Another reason Quakers have not grown more is their modesty.

BENNETT: Friends have had, especially in this century and the last century, a reluctance to go out and seek new members.

DAVIS: An additional cause may be Quaker theology itself, which takes many forms.

Margaret Fraser is dean of Pendle Hill, a Quaker retreat center near Philadelphia.

MARGARET FRASER (Dean of Pendle Hill): I think that God is revealed to different people in different ways, and there are many different paths to God.

DAVIS: But other Quakers, like Don Worden, are far more evangelical and conservative.

DON WORDEN (Evangelical Friends International): We believe that the Bible teaches that Jesus Christ is the one way to God.

BENNETT: Quaker identity is a complicated issue because there are several different varieties of Friends, and they don't always easily and smoothly get along with one another.

WORDEN: When you talk about divisions among Friends, they're pretty wide and they seem to be fairly permanent.

DAVIS: Call it the continental divide.

Generally speaking, the farther east you go, the more liberal Quakers tend to be, often valuing personal revelation more than the Bible. Some don't identify themselves as Christians.

And most eastern Quakers are called "un-programmed." They worship in the earliest Quaker tradition of silence: no minister, no sermon, no music.

But a very different tradition predominates in the west. Most Quakers there believe the Bible is the infallible word of God.

Evangelical Quakers favor a "programmed" style of worship, with sermons, hymns, a sanctuary and, in most cases, a pastor.