Columnist and former PW religion reviews editor Jana Riess (The Prayer Wheel; Flunking Sainthood) writes in her new book, The Next Mormons: How Millennials Are Changing the LDS Church (OUP, Mar.) that younger Mormons are changing the 16-million-strong church in ways that have profound implications for the future of this uniquely American religion.

This conversation has been edited for length and clarity.

Why this book now?

American millennials have shown a significant decline in religious belief and especially behavior in recent years. This is not just a “life cycle” phenomenon, meaning that it’s not just because they’re young adults who are testing the boundaries of religion or sowing wild oats or whatever. When you compare millennials to previous generations when they were the same age, there are noticeable drops. For many years American Mormonism seemed to buck the trend of young adults leaving organized religion, but recently the church’s growth has slowed in three ways at the exact same time. There are fewer converts now in this more secular environment, Mormon parents are having smaller families, and the church is having a harder time holding on to young people who grew up in the fold.

Why are Mormon millennials leaving the church in greater numbers than ever before?

One of the most interesting findings in our data was how concerned millennial former Mormons were with LGBT issues, which didn’t even rank among the top 10 reasons for older people who had left the faith. Women respondents also cited women’s roles in the church. [And] there’s a general crisis of belief. For decades, the LDS Church was able to control the narrative about its own history, even the controversial parts like polygamy. With the Internet, that’s no longer possible, and some people who grew up being taught a sanitized version of the church’s history are finding out online that the reality is more complicated. There is a general loss of trust in Mormon leaders to be fully honest about that history.

Evangelical churches also are dealing with an exodus of millennial believers. What are the parallels between these faith groups? What are the differences?

Both Mormonism and evangelicalism thrived in a previous landscape where “family values” and Republican alliances were an asset, so it’s bewildering to some older people how those same ideals are now a liability. The Barna Group’s research on millennials indicates that today’s young adults tend to perceive conservative religions as judgmental and homophobic. Independent evangelical churches can be nimble, so that’s an advantage: when you don’t have a large denominational structure you’re more fluid and can try new things. Evangelicals have experimented with worship, music, women’s leadership, etc., but the LDS Church is a bureaucratic monolith led by three men who are now 94, 86, and 85. So it’s not as easy to experiment or to change.

If American Mormonism is going to pivot to accommodate a generation that is wired for more horizontal relationships rather than a chain of command, it needs to empower local congregations to make changes, leaving behind the modernist idea that the church has to show a franchised, recognizable sameness everywhere.

Given the exodus of younger believers, where do you think the Mormon faith is headed?

This year [the church] introduced a new curriculum that might give local congregations more breathing room and reduced the Sunday schedule to two hours instead of three. It also changed the sacred temple ceremony to allow for greater equality for women. However, I would wager there’s only so far that the leaders are willing to go. They’re not going to suddenly start supporting same-sex marriage, and they’re not going to ordain women to the priesthood. The challenge ahead is how Mormonism can remain an attractive religious option in a changing society—[one in which] the pace of social change is accelerating, and people are less interested in religion in general.