As immigration has become a bitterly divisive issue, with the Trump administration denying asylum consideration to anyone crossing the border from Mexico and ramping up deportations, St. Patrick’s Cathedral will unveil a huge mural next month that depicts the arrival of immigrants to New York City in the 19th century, along with a huddle of contemporary arrivals — Hispanic, Asian, Black.

“It’s a celebration of a city that has been built by immigrants and where immigrants have been welcomed,” Cardinal Timothy M. Dolan, who is also the archbishop of New York, said in an interview in his official residence adjoining St. Patrick’s. The first major art commission in the cathedral since bronze doors were installed at the Fifth Avenue entrance in 1949, it will be dedicated during a mass on Sept. 21.

Roughly 21 feet tall, the mural, of 12 large panels, was painted by the Brooklyn-based artist Adam Cvijanovic (pronounced svee-YAHN-o-vitch), who titled it (with a slight word adjustment) after a song popularized by Elvis Costello, “What’s So Funny About Peace, Love and Understanding.” Along with immigration, he depicted a historic event dear to the cardinal’s heart: the Holy Apparition at Knock, in which 15 people in the Irish village of that name in 1879 reported seeing the Virgin Mary, two saints and the Lamb of God, a symbol of Jesus Christ, in a vision that lasted for about two hours on a wall of the parish church.

Six artists competed for the commission in 2023. Dolan and a committee of art advisers and donors favored Cvijanovic’s proposal, which is in a realistic style. “The rest of them were a little too Picasso-like,” Dolan said. “I wanted something that people could look at and see the Holy Apparition at Knock, and not that you’d have to be on LSD to figure it out.”

Cvijanovic, 64, who is self-taught, grew up in Cambridge, Mass., where his Yugoslavian-born father taught at the Harvard Graduate School of Design. He has made a career out of creating large murals that commemorate historic events and real-life characters, with a romanticism that lies somewhere between 19th-century landscape painting and portraiture and 21st-century video games and commercial advertising.

Among his past works are a series completed in 2023, at the Major General Emmett J. Bean Federal Center in Indianapolis, of floor-to-ceiling paintings of 17 unpeopled landscapes around the world where American soldiers have fought; and on an equally grand scale in 2008, a group of 16 ½ foot tall depictions of the Babylonian sets in D.W. Griffiths’ 1916 silent-film extravaganza, “Intolerance.”

The St. Patrick’s mural will be a lasting legacy for Dolan, who, when he turned 75 in February, submitted his resignation as cardinal and archbishop. (The Vatican has not named a successor.) A week before his birthday, he had strongly criticized an assertion by Vice President JD Vance that the Roman Catholic bishops were in favor of immigration because the church profited from resettlement funds. He called it “inaccurate,” “scurrilous” and “very nasty.” In fact, he said, the church loses money “hand over fist” in caring for immigrants.

As immigration became a hot-button topic, Cvijanovic worried that the archdiocese might revise its brief. “I thought they might say, ‘We don’t want to wade in these waters’ — and the opposite happened,” he recounted. “They said, ‘We want to go right ahead.’”

Like his patron, Cvijanovic felt that the mural at St. Patrick’s should be accessible. “Having the painting work for people who have no relation to the devotional activity is important,” he said, standing in front of the painted panels in the hangar-like studio in the Brooklyn Navy Yard where he had made them. “I want people to be able to see themselves in it. There’s a lot of great public art where that doesn’t happen.”

He brought up a controversial Cor-ten steel sculpture by Richard Serra that was installed in downtown Manhattan in 1981 but removed eight years later after a wave of protests from people who worked near the Federal plaza where it stood. “I love Richard Serra myself, but there was a relating problem with ‘Tilted Arc,’” Cvijanovic said. “This painting should be pretty accessible on a basic level.”

In addition to immigrants and the apparition, Cvijanovic portrayed five first responders in uniform, intended to stir memories of the World Trade Center disaster. “For the Irish and Italians who came here, usually fire and police departments is the first good job you could get,” Cvijanovic said. “There’s a long relationship between the church and the services.” Chins up, the first responders face forward jauntily, in a self-confident pose that feels very contemporary. “I wanted to make an American painting,” Cvijanovic said. “As much as I’m drawing from Caravaggio, I’m also drawing from posters for ‘X-Men.’”

The theme of immigration wasn’t the initial focus of the mural. The cathedral was dedicated in the same year that the Apparition at Knock occurred. Looking for a way to add what he called some “snap, crackle and pop” to the entry vestibule, which is known in architectural terminology as the narthex, Dolan — who visited Knock on his first trip to Ireland in 1973 and has returned many times since — thought a picture of that legendary miracle might brighten the entrance’s “dull and somber dreariness.” When he brought the idea to the advisory committee, he was encouraged to broaden his vision. “They said, ‘Show the Apparition at Knock, but let’s go from there to the immigration that flows out of it,’” he explained.

The cathedral, which is named for the patron saint of Ireland, moved uptown from its site in the NoLIta neighborhood (where the original building survives) at the tail end of the era of mass Irish immigration, which began during the Great Famine of the mid-19th century. Newcomers from Ireland constituted the bulk of the archdiocese’s worshipers at that time. Dolan’s Irish-born predecessor, Archbishop John Hughes, led the drive to construct a magnificent cathedral.

“He was frustrated about raising money,” remarked Dolan, who wore Hughes’ pectoral cross on a cord around his neck as he described the new artistic addition. “He said, ‘This cathedral will be built on the pennies of immigrants.’” Dolan noted that by contrast, raising $3 million to underwrite the creation, installation, lighting and conservation of the Cvijanovic mural took less than a day — paid for, he added with a chuckle, by “the big checks of the grandchildren of the immigrants.”

To the right of the cathedral’s central door, large panels will depict a group of 19th-century Irish immigrants, dressed in the bonnets, pinafores and caps of the period, as they descend from a ship that still holds many yet to disembark. (One has the face of Dolan’s mother.)

“I wanted this to be cool and blue,” Cvijanovic said. “And I wanted it to evoke an old film. It’s also what they were wearing. This is before bright dyes. The colors were very muted.” Hovering above them are the Virgin Mary, St. Joseph and St. John the Evangelist, the figures that were reported by the witnesses of the apparition.

Because the vision at Knock appeared in the pouring rain, Cvijanovic enlisted a gilder to apply lines of platinum and gold. On a realistic level, they represent precipitation. But he regards the gilding as more than that. “It’s talking to the Art Deco in Rockefeller Center across the street,” he said. “And it’s talking about the pipes of the organ that is across from the narthex. And I wanted it to be a representation of an abstract God. Because the gold is reacting with the light, it’s stronger than anything I can paint.”

Modern-day immigrants are depicted to the left of the door. Seated on their luggage, staring in different directions, they seem, unlike their Irish counterparts, to be waiting. Above them is the Lamb of God on an altar. In their midst is the Italian-born Saint Frances Xavier Cabrini, known as Mother Cabrini, who established orphanages and hospitals for immigrants in this country and was the first American to be canonized as a saint. Behind her is the Rev. Félix Varela, a Cuban patriot who fled to New York, where, beginning in the 1820s, he established churches that ministered to immigrant communities in Lower Manhattan.

Cabrini and Varela were on the archdiocese’s wish-list of figures for the murals, along with Dorothy Day, Archbishop Hughes, and Pierre Toussaint, a formerly enslaved Haitian American who became a wealthy hairdresser and philanthropist in New York in the early 19th century. Al Smith, a favorite of Dolan — who keeps the New York governor’s cigar humidor in his residence — also pops up in a mural, brandishing his trademark cigar.

At Cvijanovic’s suggestion, Kateri Tekakwitha, a 17th-century Mohawk-Algonquin woman who converted to Catholicism and was the first Indigenous North American to be canonized, was added to the roster. “I figured if this is all about immigrants, you’ve got to have someone to represent the people who were here,” he said. “Because the land wasn’t empty.”

To render the figures, he assembled about 20 models at a time on the deck of a house in suburban Somerset County, N.J., near where his wife, Julia Carbonetta, grew up and her parents still reside. Many of the people in the painting are her high school friends and their children. It took him half a year to sketch the compositions on Tyvek, the polyethylene wrapping fabric that is typically used for housing insulation. He transferred those templates to canvas, much as his Renaissance predecessors “pounced” full-size sketches, known as cartoons, by pricking holes and pushing through charcoal. The painting took another nine months.

“One day, there was my wife posing and a photographer and someone pouncing the cartoon, and the gilders,” he recalled. “That night I said to my wife, ‘You just saw something amazing. You saw a Renaissance studio, with all these guys here to make a painting for the church.’”

As traditional as Cvijanovic’s painterly technique is the Roman Catholic’s commitment to immigrants in New York.“Something very special in the history of the New York Archdiocese is the compassion and support of immigrants that goes back to Hughes and the 19th century,” said James T. Fisher, professor emeritus at Fordham University and the author of “Communion of Immigrants: A History of Catholics in America” (2007). He noted that during the 1950s and early 1960s, Cardinal Francis Spellman enthusiastically welcomed the influx of Puerto Ricans to the city, urging priests to learn Spanish. “They really have this legacy they can point to,” he continued. “Institutionally, the mural is going to work very well.”

Cardinal Dolan, asked if he considered receding from the political controversy that may greet the unveiling of the mural, said he never wavered.

“There is a bit of timeliness with the controversy over immigrants,” he said. “If somebody says this speaks to the sacredness of the immigrants and to a cherished part of the legacy of the church, that’s all to the good. Immigration used to be a unifying principle. It was almost patriotic to be pro-immigrant. Now it’s a cause of division. I’m hoping this will help bring people together.”