Airport police find a lot of strange things in their line of work. But when cops at Athens Airport opened the luggage of a 42-year-old monk this week nothing could have prepared them for what they discovered: a full size human skeleton. The remains belonged to a nun who had died four years previously. The monk and his accomplices had stolen the bones at a memorial service and were trying to smuggle them back to their Cypriot monastery. But why would anyone steal bones? A Cypriot Archbishop described the act as 'sacrilege'. But the monk tried to explain. The nun, he said, was such an outstanding paragon of Christian virtue that he wanted to worship her bones as holy relics. This might seem like a very strange thing to do but, in fact, Christianity has a long tradition of devotion to objects that are associated with saints or with the life of Jesus. Sometimes these 'relics' are small - scraps of cloth a saint has touched, for example, or something they used, like a pen or a rosary. But many churches and cathedrals around Europe hold holy body parts, or even entire bodies. For believers, sacred remains have mystical properties. Some are said to be 'incorruptible', meaning that the flesh doesn't rot in the usual way. Even when flesh does rot, bones are described as having a honey colour, or as giving off a sweet fragrance. This, some Christians believe, is because the bodies of the truly pious are transformed by the Holy Spirit, taking on some of the essence of divine power. Relics have been said to perform miracles, whether healing the sick or answering prayers. In the Middle Ages, unscrupulous traders made fortunes by selling fake relics to unwary believers. The Protestant thinker John Calvin was famously amused by the number of churches that believed they owned pieces of the True Cross (on which Jesus was crucified). 'If all the pieces that could be found were collected together,' he said, 'they would make a large ship-load.' Different doctrines In general, Protestant Christians are suspicious of relics. They think it's what's on the inside that counts, not how close you can get to old bits of skeleton. But many believers from older Christian traditions like Catholicism and Eastern Orthodoxy perhaps take a more magical view of the universe. They regard the divine spirit as mysterious and in some ways distant - relics are a way of getting closer to their god.