Right, but the context here is in people attending their local church. Your point is like saying that America is so diverse - it is, but how much do the different ethnicities actually interact?
Sources:
[1] https://www.jbhe.com/2018/07/americas-churches-are-becoming-...
[2] http://blogs.thearda.com/trend/featured/the-ties-that-may-no...
> The only exceptions were Catholics. Catholics were almost twice as likely to be in an intermarriage and Catholics who attended services more frequently were slightly more likely to be in an intermarriage, the researchers found.
It's more than just your local parish though. When I visited Hungary, it was amazing to go to a church where I didn't speak the language, but still be able to feel totally 'at home', because it was a church, and they were saying mass. Even though it was in Hungarian, I understood exactly what was going on. Then when I visited India, which couldn't be further from Hungary, I had the same experience.
> Despite progress in church integration, congregations remain far more segregated than the society in general. Dr. Dougherty, an associate professor of sociology at Baylor University, states that “congregations are looking more like their neighborhoods racially and ethnically, but they still lag behind. The average congregation was eight times less diverse racially than its neighborhood in 1998 and four times less diverse in 2012.”
The context here is whether churches are a good way for people of diverse backgrounds to engage and interact. I contend that they have unnecessary elements that make them worse than a non-religious community event (supernatural beliefs, explicit conformity of dress and thought, protecting predators, etc.)
Later as I grew up I realized just how unusual that sort of integration was among any congregation, not just Christian or Islamic. When I read Vivek Bald’s book Bengali Harlem: The Lost Histories of South Asian America, I realized that actually this was the norm in the 20s-60s for South Asian immigrants of all backgrounds.
This has led to some befuddlement amongst others. A black City Councilperson in New Orleans egged a crowd on to call my cousin from Islamabad names based on his origin for trying to set up a tiny house village for homeless people in a residential neighborhood in Eastern New Orleans. I roared back at him that it pained me to see someone that looked like my grandmother beating up on my cousin, mentioned that my congregation met in a formerly AME church and kept the pews for years and shame on him for assuming we are all carpetbaggers. He turned to me and said “You are presumed to be what you look like.” I’ve never been happier to see someone lose an election.