Weekends in Beijing reveal sharp differences between tourists and residents of the sprawling Chinese capital. On Saturdays and Sundays, Beijing’s most famous sights — the Summer Palace, the Temple of Heaven, Tiananmen Square — are crawling with visitors, making even Disney World at high season seem serene. Beijingers, meanwhile, flock to the flashy new shopping malls just east of Tiananmen, full of latte-swilling yuppies jabbering on mobile phones, and massive supermarkets offering everything from Parmalat milk to Peking duck. Growing numbers of Beijingers also pack into a different kind of structure on the weekend. On Sundays, the capital’s government-registered Protestant