Q: Why did you write this book?
A: I think religion is extremely important in America today. All of our research shows that, and I wanted to get empirical data about religion out there, rather than just speculation.
We here at Gallup have had a tracking project since 2008. We do 350,000 interviews a year, which is a huge and unique data set that nobody else has. And personally, I grew up in a religious background and always found it interesting.
Q: What's the most important trend in American religion today?
A: One trend that I'm asked a lot about is the rise of the "nones," about which there's a huge amount of publicity, but which is often misinterpreted. When Gallup asked the question about religious identity back in the 1950s, almost zero would say they have "none." People would say "Baptist" or "Catholic" even if they were not particularly religious. Now, 18 percent of Americans, according to Gallup polls, say they do not have a particular religious identity. That doesn't mean that 18 percent are atheists only 5 or 6 percent say they don't believe in God but people are changing how they express their religiosity.
Q: Despite the rise of the nones, you say that religion is poised for a renaissance in America.
A: Well, I wouldn't predict it. But it certainly is a possibility that, rather than continuing to decrease, religious identity could increase. We've been analyzing data from 350,000 interviews since 2008, and 2012 showed the lowest increase in the percentage who said they have no religious identity, so that might be leveling off.
Q: Do other trends point to a religious revival?
A: If you look at age, the baby boomers are approaching 65-85 years old, which we've seen as the most religious age group for decades. It's a reasonable expectation that the huge group of boomers is going to become more religious, and because they are so big, they'll make the country more religious in the aggregate.
In addition, the country's increasing Hispanic population tends to be more religious. Religion has been correlated to health, so more people may seek out religion because it's good for them. And Americans are migrating to states that are more religious, which tends to make [the travelers] more religious.
Q: Gallup uses worship attendance as a key barometer of religiosity. But haven't studies shown that Americans often overstate how often they attend religious services?
A: That's probably true that people overstate how often they go to church. But it's a generalization. It doesn't mean that someone attends church 52 weeks a year. But we've found that church attendance is a good surrogate for religiosity. People who report to an interviewer that they attend services often are in fact more religious than others, even if they don't actually attend services as often as they say they do.
Q: You write that mainline Protestants are pretty much doing everything wrong in terms of growing their churches. Why's that?
A: For any group to grow, whether it's a country or a church, you have to have more people coming in than going out. For example, the Catholic Church holds its own in terms of percentage of the American population because of the in-migration of Hispanics. But there is no massive in-migration of Protestants. Secondly, there's been no evidence that they've been able to evangelize effectively. And thirdly, one way you grow is to have high fertility rates. Mormons are doing that well because their theology encourages big families. But Presbyterians, for example, have less children on average [than other Americans].
So, if you look at all the ways churches could grow, the mainline Protestants haven't been able to hit the nail on the head with any of them.
Q: Why do you propose that the government and companies promote religion as a means to reduce health-care costs?
A: That certainly is controversial. We have separation of church and state in this country. But the correlation between religion and well-being has been established by Gallup and many other organizations. The question is causality: Maybe healthier people choose to be more religious. But it's clear that religious [people] are less of a drain on our mental and physical health systems. So, a company may want to give discounts for employees who attend church four or five times a month, just as many give discounts for employees who go to the gym. If America were to become more religious, and this is controversial, it would become healthier.