So many bits of the ‘true cross’ were scattered across Europe that in the day of Calvin, in France, they were carried in processions and venerated by the faithful and treated with contempt by Calvin himself –
‘Here comes the true cross!’ Again there was a rushing and shouting, citizens and strangers crushing one another.—‘It is not the only one,’ said the reformer, ‘there is no petty town or paltry church where they do not show you pieces; and if all were collected together, there would be a load for a great barge, and three hundred men could not carry it.’
His biographer goes on to remark more fully
In 1544 he published a little treatise which he calls “An Admonition,” showing the advantages which Christendom might derive from an Inventory of Relics. It is one of his most popular productions and affords unlimited range for his powers of irony and sarcasm.
He begins by saying it would be a good thing to catalogue all the relics which are said to exist in Italy, France, Germany, Spain, and other countries, and he suggests that as the monks have very little to do they might employ their time usefully in making such a catalogue. He himself has no complete knowledge, but he is aware that if all the relics throughout Christendom were catalogued, it would be seen that every apostle had four bodies at least, and every saint two or three. The relics of Christ are very numerous.
Besides the teeth and hair, the monks of Charrox give out that they have the piece of skin cut off at His circumcision. His natural blood is shown at a hundred places, sometimes in drops and sometimes in goblets-full. In Rome there is the manger in which He was laid at His birth, the linen in which He was swaddled, His cradle, and His shirt, and the altar on which He was presented in the temple. Elsewhere may be seen the waterpots of Cana, the wine with which they were filled, the bread used at the Last Supper, the dish in which the Paschal Lamb was placed, the knife with which it was cut up and the towel used to wipe the disciples’ feet. No less than fourteen nails are shown as the nails used in the crucifixion. What remains of the crown of thorns would make a substantial hedge, and what remains of the true cross would fill a ship.
The purple robe in which Christ was exhibited to the people is shown at two places. Relics of the saints are even more numerous. There are the milk of the Virgin Mary, the shoes of Joseph, the sword with which the Baptist was beheaded, and so on. Anna, mother of the Virgin, has one of her bodies at Apte in Provence, and another in the Church of St. Mary Insulan at Lyons. Besides, she has one of her hands at Treves, another at Turin, and a third at a town in Thuringia which takes its name from it. Lazarus likewise has three bodies, one at Marseilles, another at Austum, and a third at Avallon.
The entire body of Petronilla, St. Peter’s daughter, lies in the church at Rome dedicated to her father, but there are some separate remains in the Church of St. Barbara, and there is another of her bodies in the possession of the people of La Maine. It is alleged to cure fevers. What evidence can be produced to show which if any of these relics is genuine? At present you may be worshipping the bones of a horse or a dog when you believe that you are worshipping those of a saint. Nor can the ring and comb and girdle of the Virgin Mary be revered without the risk of discovering that the articles in question were really some part of the dress of a strumpet. For those who profess the name of Christ the best thing is to abolish the heathenish custom altogether as a thing that leads to idolatry and that is offensive to God.*
The absurdity of relic adoration is plain for all to see if they but have one good eye.
*Hugh Y. Reyburn, John Calvin: His Life, Letters, and Work (London; New York; Toronto: Hodder and Stoughton, 1914), 212–213.