In the United States, fewer young Americans identify as religious or attend regular services than members of any other living generation. People in their 20s and early 30s account for more than a third of the country’s “nones,” an academic nickname for the religiously disaffiliated. Religion is no longer the mode through which many people live their lives, and this relatively new state of affairs affects even those who remain religious: It opens up the possibility of beliefs and practices that are not simply inherited, but actively chosen.

This makes some people nervous—for the future of religion, for the strength of cultural mores, and for the health of American communities. And perhaps these worriers have a point. Religion tends to make people happier, healthier, and more civically engaged. It creates a foundation for communal and social life, provides a common set of behavioral rules for people to abide by, and can be a useful guide for navigating the exhaustion and pain of everyday life. Looking out at a generation full of folks who don’t go to church or synagogue or mosque, some sociologists and commentators can’t help but wonder: What will become of us?

But even as the country is becoming somewhat less religious, it is also becoming more religiously diverse. This is true around the world: People everywhere, especially young people, are changing religions, moving locations, and shifting the way they follow rituals and laws. The United States offers a distinctive case study for this phenomenon: Immigrants are introducing their cultural practices into so-called old-time religion; formerly powerful and monolithic-seeming groups, like white Protestants, are fracturing; long-standing assumptions about everything from the relationship between religion and government to acceptable expressions of sexuality are no longer firm.

Religious choices are proliferating as conscious choices. Even as they create some of the most intense and hate-filled conflicts in American politics, they’re also a source of creativity; these choices help people shape their identities and form a sense of self. This might include the choice of who to marry, whether to convert, and how to spend a Friday night or Sunday morning. Some face the dilemma of staying in a religion that upholds tenets with which they disagree, or leaving a religion they love. People must decide whether to be public and even political about their faith, or whether to relegate it to the privacy of their home. Even those who feel apathetic about organized religion face daily questions about how to treat others and how to act. Some embrace a kind of secular humanism; this is, itself, a claim that each person can individually determine his or her own code of ethics.

Religious choices can also be a source of anxiety, and not just for the people facing them. The brains of the young sometimes seem packaged in black boxes; experts spend incredible amounts of time picking apart and predicting their decisions. But perhaps no Millennial mystery evokes as much anxiety as their religious beliefs and practices—particularly when it comes to the “nones,” a label that provides excellent fodder for sociology-of-religion puns, if not conceptual clarity.

Viewing youth and religion through this framework, though, may obscure more than it reveals. For one thing, the category can be misleading. People who don’t identify with a particular religious group aren’t necessarily non-religious or non-believers. Many embrace some sort of ritual practice, and relatively few describe themselves as atheists or agnostics. It’s true that a growing number of young people are drifting away from religious institutions, but it’s also true that a significant portion of young Americans still attend worship services, pray, and believe in God. And it’s likely that at least some people will find their way back to church or wherever they may go as they get older: Research suggests that some men and women reconnect with religion when they start going through big life events like getting married and having babies.

Perhaps no Millennial mystery evokes as much anxiety as their religious beliefs and practices.

The bigger problem with “none-ness” is that it suggests a clean narrative arc for the past and future of religion: an inevitable, measurable decline. If young people don’t care about religion, the thinking goes, that necessarily means the United States will become a much less religious country over time. This is not a new theory; sociologists and historians have been predicting the end of religion for many decades. In the 1950s and ’60s in particular, Western scholars of religion focused on the certainty of secularization, only to see much evidence to the contrary in subsequent decades. From a global perspective, the share of religiously unaffiliated people is expected to decline in the next four decades.

These narratives also assume that religion can be quantified. Church attendance may be down, but that doesn’t say much about the people finding church outside the walls of a sanctuary. Certain denominations may clock more hours and count more bodies at their worship services, but that may say more about those institutions than the people who participate in them. Polls, and especially polls about religion, have limits. They often depend on small samples and low response rates, and they rely on people to describe themselves in a coherent way—something that’s not, it turns out, so easy to do. They sometimes privilege the culture and practices of certain groups—e.g., Christians, white people—over others. Their purpose, fundamentally, is to sort messy phenomena into neat categories. But religion—a sprawling sphere of life that encompasses everything from saccharine celebrations to the search for ultimate meaning—religion is not neat.

Over the next two weeks, we will be sharing stories about young Americans’ religious choices. These will be stories for people interested in politics, dating culture, legal battles, and the many rich textures of ritual observance, among other topics. Because religion stories are not just stories about religion. They are studies in how people understand and navigate their identities, and the conflicts that might ensue. They are ways of understanding communities, dissecting politics, and critiquing systems of power. Likewise, religious choices are not just choices about whether to be religious. They show how people try, or don’t try, to coexist, and how they grapple with the uncertainty of living. The way young Americans wrestle with these choices will not only shape their futures. It will shape the future of the country.