Imagine a huge dish of beaten gold, worked from edge to edge with fine bas-relief. At its centre kneels Jesus, barefoot saviour of the poor and the needy, washing the feet of his disciples.
The dish itself, made during the reign of Charles II, looks too big to carry, and almost too heavy to lift. It is of an almost unseemly and disgusting size and opulence. What would Jesus have made of such a representation of himself? Would he have felt a little queasy at the very sight of it? Would he have flung it out of the Temple as evidence that the church was too much in the service of Mammon?
Such was the English church, that great patron of the goldsmiths and the silversmiths, from the Middle Ages onwards. And this exhibition of about 300 exquisite examples of sacred gold and silver spanning about 1,200 years is, from first to last, a kind of triumphal celebration of all the money that was spent to prove that Christianity was a spiritual force underpinned and legitimatised by temporal power. And it is, of course, enthralling, because money buys you splendour, no matter how ethically dubious the enterprise.
The staging of the show, within the 19th-century razzmatazz of Goldsmiths' Hall, is an exercise in the tricksy conjuring of a mood of awestruck reverence. We enter the main display on the first floor through a faux-Gothic arch. To our right, we stare at a false church window. The staging of the pieces is hushed and reverential. Cabinets are often bathed in a yellow light. A beautiful male voice is singing church music, we soon notice. It is drifting down through the ether, calming us into the correct frame of mind to stare at the Archbishop of Canterbury's Primatial Cross of 1883, designed by Thomas Bodley, fashioned from silver-gilt and studded with diamonds, rubies, emeralds, sapphires, garnets, pearls and rock crystal, and displayed amid the richest of rich purples.
At a certain point, a disgruntled elderly engineer from Kettering tells me that he is here under false pretences. He had expected to see jewellery, not church plate. Jewellery? He need go no further than William of Wykeham's wonderful 15th-century Girdle, with its string of thumbnail-size gems. It's made from silver-gilt, enamel, rock crystal, and pearls. A magnifying glass proves to us that there is nothing religious about the decoration or the design of this piece. The plaques of enamel, all hinged, show us images of monkeys, hares and deer. Is this not jewellery in all but name, and perfectly suited to a man – Bishop of Winchester and founder of New College, Oxford – of such swagger?
The show is a not an easy one to navigate because we enter it at its end on the ground floor – the most valuable pieces are the oldest, and it was important for security reasons to keep them as far away from the ground-floor exit as possible – and then proceed up the stairs in pursuit of its beginning, deep in the Middle Ages. Although the pieces are captioned within their cabinets, it would have been easier had they been numbered, as it is not always evident which caption belongs to which object.
Nevertheless, the show teems with pleasurable curiosities, no matter at what point you enter it. There is, for example, a marvellous display of 17th-century Steeple Cups, each as tall and as steepling as the name suggests. Some of the most interesting pieces come from parish churches, and not from the great cathedrals, such as a silver cup, dated 1612, in the form of a bunch of grapes, borrowed from a church within the diocese of Chelmsford. Would Jesus not have preferred to bite down on real grapes?
To 12 July (020-7606 7010)