I must admit that I never knew the lyrics to "Silent Night," that most famous of Christmas songs, until I was well into the prime of my life. There was no reason I should have, though. Growing up in a tightly knit Orthodox community in New Jersey, I attended Jewish day schools and Jewish camps and was active in Jewish youth movements, as insulated from the Gentile world as anyone could possibly be. My first real contact with non-Jews came during my college years in New York, but even then, most of my closest friends were Jewish, and my Christmas...