At the Dongsan Korean Reformed Church in Yonkers, N.Y., the cafeteria is twice the size of its worship space. The spacious, high-ceilinged room is filled with more than 40 round dining tables encircled by white folding chairs. After the 11 a.m. service every week, lunch is served and the tables fill up like a high school cafeteria.

On a recent Sunday, hungry, boisterous parishioners formed long lines for their servings of miyeok guk, a savory seaweed soup, which burbled away in three giant pots on the stove. Everything is made from scratch, and with good vibes only.

“You have to cook with joy or the food won’t come out right,” Soon Geum Jang, 73, said. If there’s anything difficult about feeding 400 to 500 parishioners every week, the kitchen’s head chef Young Hee Kim, 65, said it’s producing that sheer volume of food. But cooking together, with friends, “it’s not hard.” Every Saturday morning, Ms. Kim and her team meet early at the church to prepare food for the next day’s lunch.

According to a recent study from the Pew Research Center, 59 percent of Korean Americans identify as Christian. But that number used to be even higher. For decades, church lunches have been pivotal spaces for Korean immigrants as they established themselves in the United States, and these meals continue to flourish as hubs of community bonding for many who are the first generation to arrive here. More than just a meal, they are a key opportunity for conversation, gossip and fellowship.

But the Korean Americans born here are now finding third spaces beyond work and home — that aren’t church — to be with other Korean Americans. In a rapidly evolving world where Korean pop music, food, film, culture and community can be found virtually anywhere, the after-service lunch is becoming a less central experience for younger Korean people.