BETHLEHEM, West Bank, Dec. 20 - In the town where Christians believe Christ was born, the Christians are leaving. Four years of violence, an economic free fall and the Israeli separation barrier have all contributed to the hardships facing Palestinian Christians in Bethlehem, one of the largest concentrations of Christians in the region. An estimated 3,000 Christians in the Bethlehem area have moved abroad since the Palestinian uprising began in 2000, according to Bernard Sabella, an associate professor of sociology at Bethlehem University who has tracked the issue. While some others put the number a bit lower, there is a...