As the sea of commuting humanity marched through Union Station on Wednesday morning, something was attracting stares. Some gawked openly; others stole quick peeks as they trooped past.

Matt Norton removed his ear buds and walked directly up to the priest with a black cross on his forehead and a bowl of ash in his hand.

“What’s the deal?” Norton asked.

“It’s Ash Wednesday. It’s a reminder of our dependence on God,” said the Rev. Peter Schell, a 32-year-old Episcopal priest, at once explaining the start of Lent and the reason he was offering to etch the mark of Christian faith on the foreheads of passersby as they headed for offices, which, for the most part, would appear faith-free.

“Huh,” Norton said noncommittally before heading off to his job as a mobile app designer for PBS.

In fact, Norton, a Catholic, had a lot more to say about wearing ashes. He planned to get them during a midday Mass near his office. On Ash Wednesdays, he’s picked the time to receive the mark based on “how self-confident I’m feeling” about sharing his beliefs. It depends on how empathetic he’s feeling toward people who have felt rejected by the Catholic Church, or religion in general. Or whether he feels he’s wearing his Christianity for pure, selfless reasons and not “showing my faith in a pompous way.”

This is the sort of reflection Schell and other priests had hoped to bring about when they took to Union Station and a handful of Metro stops around the region at morning rush hour to offer ashes and a prayer — an acknowledgment that many Americans are no longer going to houses of worship, so the houses of worship need to come to them.

More than 200 Protestant congregations across the country now offer ashes in public places on Ash Wednesday, according to Ashes to Go, a national organization that began the practice about five years ago. The day marks the beginning of Lent, a 40-day period of reflection and fasting that ends on the Thursday before Easter.

The public displays come at a time when Americans, particularly younger ones like Norton, are more cautious about openly professing their spiritual identities, according to two decades of data from the Barna Group, a major research firm on U.S. religion. One reason is that, in an increasingly pluralistic society, some see overtly religious jewelry or T-shirts, or even an ancient, liturgical ritual such as ashes during Lent as a possible imposition on others who do not share the same beliefs.

The trend also stems from a fear of oppression by a secular culture and partly from a personal challenge, said David Kinnaman, president of Barna Group and author of several books on young Christians. In a society questioning the very truth of God, what do you really believe?

“In the past, evangelism didn’t have that high a standard; you were sort of signing people up for something they already were predisposed to accept,” Kinnaman said. “Today it’s about people asking: How does that translate into real transformation? When I wear something, what is this saying about me?”

An increasing number of Americans describe themselves as “unaffiliated” with a traditional faith group, including some who call themselves Christians, and the practice of wearing ashes for Lent is primarily associated with members of traditional Christian denominations, such as Catholics and Episcopalians and other Protestants.

Based on national faith statistics, the vast majority of the hundreds of people who walked Wednesday past Schell, and two lay ministers from Calvary Episcopal Church on Capitol Hill, would at minimum describe themselves as Christian. But their responses to being asked to wear their faith on their forehead varied widely.

About 100 commuters approached during the two-hour window to receive ashes and the traditional prayer: “Remember that you are dust, and to dust you shall return.”

Some almost charged over when they saw the untraditional, pop-up chapel in the crowds, cutting off other commuters. Some appeared surprised, paused and then approached.

“Baptists don’t do ashes, but I’m versatile with my religion,” said Tina Buckmon, 53, who was heading from the bus to her job as a cook at a child-care center next to the station. “It doesn’t matter where it comes from, everyone needs a blessing. I’m with all religions.”

Buckmon said she doesn’t wear a cross because she believes Jesus has risen and is no longer on the cross. She is deeply religious, describes having premonitions and believes God has used her in daily ways to help others. Yet she doesn’t talk a lot about her faith at work because “some people don’t want to hear it.”

Most commuters walked past the priest, who stood between a Pret a Manger and an Au Bon Pain, with no acknowledgment. Others stole furtive looks that could have been interpreted as curiosity, or guilt. A few gave a small smile and a nod, the obligatory kind you’d give to a person ringing a Salvation Army bell at Christmas.

One man thought the priest was actually a man in costume making fun of Christianity. Another launched into a rap about the Rapture.

Some just watched from afar. Jason Williams, 37, was in town from Annapolis and was having some oatmeal and an iced coffee when he noticed the trio. A “non-practicing” Catholic, Williams said he’d worn ashes at various times in his life and would “absolutely not” think it would be hard to wear them in a diverse place such as Washington.

Asked whether he’d feel comfortable discussing all this at work, his answer was quick: “No, no, no. That’s a professional environment.”