Brian Whelan has arranged nine of his “holy city” paintings to form a 9-by-12-foot mural for an exhibition that is on display at the Washington National Cathedral through next month. (Courtesy of Brian Whelan)

Over the past two decades, Brian Whelan has created countless paintings of holy cities, which he describes as “thin places where heaven and Earth seem so close as to actually touch.”

Whelan, who lives in the western Loudoun County village of Waterford, is particularly fascinated by the idea of cities where shrines, temples, cathedrals and mosques attract pilgrims of the three Abrahamic faiths — Judaism, Christianity and Islam — coexisting in peace and harmony.

Nine of Whelan’s paintings are on display in “Holy City,” an exhibition running through January at the Washington National Cathedral. The works are arranged in rows of three, forming a 9-by-12-foot mural in which the scenes blend seamlessly. Having exhibited his works at the cathedral previously, he approached officials about displaying his paintings of holy cities, which he had completed over two years.

Whelan was born in Britain and lived there most of his life, but he considers himself Irish. His parents were from Ireland and immigrated to London before he was born. Whelan grew up in a “London-Irish” community where Catholic schools, the church and Irish pubs were integral parts of daily life.

Although many of his paintings have religious themes, he said he doesn’t want to come across as “pious or proselytizing.”

“I was brought up a Catholic, but I certainly didn’t get high marks in my religious education,” Whelan, 59, said. “I can definitely remember being at the bottom of the class.”

He spent seven years in art school, including the Royal Academy of Arts. Afterward, he “needed seven years to forget what I had learned over those seven years to be able to start [painting] again,” he said.

“When I was at each of these places, I would always dabble in something religious,” he said, even though his instructors often disapproved. “The history of art is the history of religious art, so I’m just drawing on this resource.”

Whelan met his wife, Wendy Roseberry, in Britain. They married in 2006 and moved to Virginia in 2013. Roseberry, an American, already had a house in Bluemont, but Whelan described it as “all glass,” with no place to hang a painting.

They eventually found a more suitable home in Waterford. Parts of the house date to 1790, when it was occupied by the only Irish family in Waterford, Roseberry said. Its walls are filled with Whelan’s paintings.

Whelan said he was first captivated by the idea of holy cities about 20 years ago, when he asked an art class of eight senior citizens to use their imaginations to depict such a city.

The purpose of the project was not to create a scene of Jerusalem, Whelan said, but rather an “aspirational vision” of what a holy city might look like.

In his paintings, Whelan uses bright colors to create rich, playful scenes in which churches, mosques and synagogues on hillsides lean into one another at precarious angles. Religious symbols — the cross, the Star of David, and the crescent moon and star — are intermingled with images of nature and peace, such as white doves and a rainbow.

Each scene also includes a pilgrim, which Whelan considers to be essential to the idea of a holy city.

“The ‘holy cities’ that I have painted . . . speak to that which pilgrims have always sought: a place where one’s soul can find refuge and rest,” he said at the exhibition’s opening in September, which was timed to coincide with the 15th anniversary of Sept. 11, 2001. The pilgrims are “drawn not so much to a place, as to the possibility that such a place exists,” he said.

The paintings also incorporate shiny pieces of foil wrappers from chocolates and other candies from around the world. The foil adds luminosity to the scenes and suggests that the religious structures are merely shells that invite people to come inside to find much richer treasures, he said.

Whelan said he puts different colors and shapes together to create harmony out of religious diversity.

“And, in fact, the hard lines between the mosque and the church and the shrine and the synagogue — that is part of the painting,” he said. “It’s when you get further and further away, it starts to blur . . . which is sort of like a unity. But I want to celebrate the differences.”