Even in 21st century, diversity has a strong "non geographic" character
E.g. Tamil families which migrated to Mumbai in 1940s still remain Tamil. They have not become Maharashtrians
Bengalis in Delhi remain Bengalis. Not just for 1 generation. But for 2-3+ generations
Yet, they remain Tamil. They are not maharashtrians or North Indians
Nor a Maharashtrian from Bombay
But rather Bombay Tamils like themselves!
What it means is - your geographical situation does not change your culture
Your culture is not tied to the land where you live
It is tied to endogamy and ancestral traditions
Adopt Christian names etc
In contrast, Indian Americans follow Hinduism, enrol on arranged marriage bureaus even in the 2nd generation!
So very few of them convert to Christianity
Sharp contrast to Chinese Americans among whom Christianity is a popular choice particularly after 1 generation in US