Early in his church-planting work in New York City, the Rev. Tim Keller focused on what he called the Center City, which started in lower Manhattan, near Wall Street, and extended past Central Park.

The Presbyterian Church in America seminary professor camped in the old Tramway Diner under the 59th Street Bridge at 2nd Avenue, asking New Yorkers probing questions about their lives. He dug into the socialist Dissent Magazine to learn the city's secular lingo.

But New York was already evolving in 1989, when Redeemer Presbyterian Church opened its doors two weeks after Easter, said Tony Carnes, leader of the "A Journey through NYC Religions" website.

Changes began in the 1970s in the city's boroughs "with more internationals arriving from all over," including Global South cultures in which "no one doubts that faith is an important part of life," he said, reached by telephone. "It took time to see these changes affect Manhattan, but they did."

In 2000, Carnes' team found -- through a face-to-face census with church leaders -- 120 evangelical congregations in the Manhattan Center City. That number reached 197 a decade later, 251 in 2014, 308 in 2019 and are expected to near 370 in 2024.

"We know there are others, because we hear things all the time," said Carnes. "We just haven't found them all -- yet."

For decades, researchers considered New York City a lab for the brand of secularism defined by Harvard Divinity School historian Harvey Cox, author of the influential "The Secular City" in 1965. In a famous quotation, he noted: "Secular Humanism is opposed to other religions; it actively rejects, excludes, and attempts to eliminate traditional theism from meaningful participation in the American culture."

However, at sidewalk level it's obvious that there are "two New Yorks," noted Carnes. While secularism remains dominant in mass media, academia and other parts of the cultural establishment, the reality is more complex in Queens, Brooklyn, the Bronx, Staten Island and now parts of Manhattan.

It's hard to consider the Big Apple a truly "secular city," when considering the rising number of New Yorkers who are Muslims, Orthodox Jews, Hindus and evangelical and Pentecostal believers in Latino, Black, Asian, white and interracial flocks.

"Secularists and progressives … are still here and their power is real," said Carnes. "But sometimes they cannot see the complex reality that's around them."

During the decades of Keller's ministry, which ended with his May 19th death, it became clear that New York has become what some researchers call a "post-secular city," a multicultural quilt in which secularists still hold most of the high-cultural ground.

"The post-secular city is a contested city between varieties of religion and nonreligion. New types of leaders, ethical questions and communal identities raise all sorts of contested areas over which neither the secular nor the religious have exclusionary authority," noted Carnes, in an essay at "A Journey through NYC Religions" published after Keller's death.

This tension made headlines when Mayor Eric Adams told a March interfaith audience that helping young people now requires "instilling in them some level of faith and belief."

The Democrat added: "Don't tell me about no separation of church and state. State is the body. Church is the heart. You take the heart out of the body, the body dies. I can't separate my belief because I'm an elected official. When I walk, I walk with God. When I talk, I talk with God. When I put policies in place, I put them in with a God-like approach. … That's who I am."

Carnes noted that the mayor, a former New York City police officer, used religious language because he knew it would connect with most of the coalition that elected him, which included working-class New Yorkers, Black and Hispanic church leaders and, eventually, Orthodox Jews.

"Now even the mayor's office in New York City has appointed an evangelical pastor as Faith-Based and Neighborhood Initiatives director" and this choice was contested by many "secular left and LGTBQ activists," wrote Carnes. "But the city's public square is not the exclusive playground of the secularists, so they lost the fight." Meanwhile, "religionists can't assuredly promise the rising of a new Jerusalem, Mecca or other sacred firmament out of the watery mess. Neither side is very happy drifting with each other in this liminal state."