LAST year, as every year, I went rather wearily to the school Nativity play. And last year, as every year, the same story was told. An angel in a white sheet told a curiously unsurprised Mary that she was going to have a baby. Joseph, grey-bearded and leaning on a stick to indicate his advanced age, was slightly upset but was quickly reassured that his wife was still a nice Jewish girl. Mary and Elizabeth had some vaguely theological conversations during Mary's pregnancy, and then, ...