The mainline churches are not alone, however, and the declining appeal of a clerical career among Christian and Jewish youth in a country that considers itself religious raises questions about the future viability of the very institutions that have fostered that faith. Are they in a position to reverse that decline, and what might it take?
Religious communities and seminaries are starting to grapple with that question, and some working on the cutting edge foresee changes more radical, though not more bleak, than others may anticipate.
The current picture is unsettling. The Roman Catholic Church not only has fewer young men joining the priesthood, it is already grappling with a severe overall shortage. So far, the shortages for Protestant and Jewish denominations are largely in rural areas. Many middle-aged men and women have chosen ministry as a second career in recent decades, but that means fewer years of service before retirement.
"When I was in seminary in 1988, there was a glut of clergy," says the Rev. Bonnie Perry, the young rector of All Saints Episcopal Church in Chicago. "Now people are waking up and realizing that everyone is going to retire [soon], and there is no one to take their places."
Just as crucial is the import of a younger clergy in attracting and keeping teens and young adults in congregations.
"It is a real challenge for the church in America, because your under-30s are the generation walking away from the church," says Edmund Gibbs, professor of church growth at Fuller Theological Seminary, in Pasadena, Calif. "Very few in leadership really understand the Gen X and Gen Y generations, [which are] looking for a different kind of church."
Two recent studies highlight the stark picture. A survey of mainline churches by the Louisville Institute in Kentucky showed a startling change over the past 25 years: In 2000, ordained clergy 35 years or under represented only 4 to 8 percent of the totals, while in the mid-'70s, they constituted 20 to 25 percent.
A survey of students entering US seminaries in 1998, by Auburn Theological Seminary in New York, confirmed the profession's diminishing appeal among young adults compared with law and medicine. The average age of seminarians was 35, while that of law students was 26 and of medical students, 25. Roman Catholics are the oldest (averaging about 40 years), followed by mainline, evangelical, and rabbinical students (30 years).
"It appears evangelicals have an easier time attracting young people than mainline Protestants," says Barbara Wheeler, Auburn's president. "They have a much more vigorous network of youth and campus organizations."
Brad Smith, president of Leadership Network in Dallas, a group working nationally to help churches become more effective, has seen alternative churches spring up in several locations, led by and serving young people.
"It's not just generational, but a deeper issue now labeled as the shift between modernism and post-modernism - a different way of thinking, perceiving, and shaping information," he says. Some see this as "the first time in 300 years - since the Enlightenment - we've had a shift of this severity in the Western world."
And it's wholly pertinent to forms of worship. "A presentational Sunday worship experience - such as that you'd find at Willow Creek [the church near Chicago that first ignited the megachurch movement] doesn't make sense to them," he says. What's important is engaging in the process, experiencing God and creating community at the same time.
The worship services in churches "planted" by in-tune young clergy may look disorganized to others, Smith adds, but they are interactive, tend to emphasize narrative and not logical presentation, leaving it to the audience to tie the threads.
Given the tremendous need, why aren't more college graduates heading for the seminaries as they did a few decades ago? The profound social and cultural changes have a lot to do with it, many say, affecting the society at large and the churches. Seminaries have yet to adjust to the changes.
The influence of organized religion and the status and prestige of clergy have diminished. "Today, it's not cool to be a cleric," says Niles Goldstein, a young rabbi who has started a New Shul in New York City aimed at the "unchurched."
The relatively low pay for an increasingly demanding job has made pastoral life less attractive even to those already ordained. Attrition is high, as many pastors find it difficult to manage the conflict that change can bring or are unable to afford sending children to college. Why encourage others to seek the job? Smith couldn't agree more. Not only was he discouraged early on from his desire to be a minister because others thought it wouldn't use enough of his talents, but he sees people of all ages, including highly successful businessmen yearning for a second, more meaningful career, finding churches unable to see how to effectively utilize their remarkable gifts.
The challenge for denominations and seminaries alike is to embrace the reality of cultural change and consider more profound kinds of transformations. Part of the problem, says Rabbi Goldstein, is that "our seminaries tend to be overly cerebral or academic, and the spirituality a lot of younger people are looking for doesn't seem to be present." Those seminaries need to involve exemplary pastors in their teaching program, Wood says.
Young people who have entered the profession often find it a struggle to make their voices heard within their denominations, and some are forming informal networks to try to have more impact.
Smith sees the culture driving churches to a crucial decision point: "Do we retreat from this change and serve those who are not making that change, or do we start reinventing how we do church? It's a particularly painful time," he says, "probably like the Reformation."
The process some large baby-boomer churches have gone through is instructive. They've started a youth service, which grows into an alternative church. For various reasons - conflict over style or money - the young clergy break off and "plant" a separate church. "That pattern is happening all over," Smith says.
While some churches choose to serve older congregations and others cater to the young, many will still aim to embrace all generations. Goldstein says his synagogue is a marriage between tradition and experimentation, and attracts people of different generations who "had written off religion." Perry, whose congregation has an average age of 36, says creating meaningful connections is what's needed.
"We all want to know we are loved by God, and that we have a gift from God that can change the world at least a little," she says. "If you can create communities that do that, people will say, 'That's cool.'"