Simon Taylor was on his way to an appointment in Flatbush, Brooklyn, when he pulled into a local filling station one afternoon last week. It was a lovely fall day in New York, but as he began to fuel up, the climate turned sour: Another customer, spotting the skullcap atop Rabbi Taylor’s head, launched into an expletive-laden rant about how much he hated Jews and then, when the rabbi photographed his license plate, started chasing him with an upraised fist. Taylor, a 58-year-old father of five who oversees social services and disaster relief programs for an umbrella organization of Orthodox...