Jewish citizens reflect on their faith to mark Yom Kippur.(Originated from Knight-Ridder Newspapers)

To be Jewish in America, where the culture is predominantly Christian, where your faith is outnumbered nearly 50 to 1, can be challenging. It can also be defining.

This may feel truer in places such as Grand Forks, N.D., and Wichita, Kan., where synagogue affiliation is numbered in dozens and hundreds, than in cities such as Miami, where some synagogues count over a thousand families as members, and where, in some areas, a Jew needs only to step onto the elevator of her condominium to be reminded of her religion.

But Jews everywhere speak of cherishing a fragile and precious sense of group identity.

The identity seems especially strong on the high holy ...