Recently, three totally disparate things have been making me think about Heaven.The first is that my garden has been invaded by fledgling wheatears. Wheatears are among my favourite small birds – the adults are so chic with their smartly patterned black and white tails and their black eye stripe making them look as though they are wearing sunglasses, but at the moment the young still look fluffy and unfinished. They are feeding away to gather strength for their autumn flight all the way to West Africa. The ones that breed in Greenland will pass through later in the year for the same destination, making them serious long-distance migrants.The second thing is the hideous displacement of people – Christians, Shiite Muslims and others – in Syria; and my awareness of how long