"If you want to get rich," advised L. Ron Hubbard, "start a religion". Today's news from Kerala, that archaeologists investigating the long-neglected vaults of the Thiruvananthapuram temple have unearthed treasures worth up to £12 billion , suggests that his maxim wasn't simply a reflection of 20th century cynicism. God has long been where the money is.
The Indian temple's treasuries haven't yet been fully explored, but already they have yielded up tons of gold coins, sacks overpouring with diamonds and rubies, and spectacular individual items including a six-metre long necklace. Kerala chief secretary K Jayakumar estimated the total value at 500 billion rupees (around £7 billion); while other sources put it at more than $23 billion. No-one really knows, of course, and such figures are highly speculative. But it's certainly an awful lot.
The treasure represents the accumulation of centuries. The temple dates back to at least the 8th century and for many years was under the protection of the royal dynasty of Travancore. Its position at the hub of trade routes helped it grow rich with the offerings of passing merchants and wealthy pilgrims. Much of the wealth, though, seems to have been locked away and forgotten about until a recent decision of the Indian Supreme Court ordered the contents to be itemised and secured.
Though the quoted sums may equal the entire Indian education budget, there seems little prospect of a sell-off. This is sacred treasure, after all, not just loot. The hoard may make the temple of Thiruvananthapuram officially the country's richest, but there are several others whose wealth is known to run into billions of dollars and many more whose precise holdings remain unclear.
It has also just been revealed that the guru Sai Baba -- best known for his Afro hairstyle and for performing a conjuring trick with "sacred ash" -- left behind property worth around £5.5bn  when he died in April. The world's richest Christian pastor, by contrast -- Nigeria's Bishop David Oyedepo  -- has to make do with a paltry $150 million, although that is enough to keep him in four private jets as well as homes in London and the United States.
In scenes strangely similar to those in Kerala, officials at Sai Baba's ashram recently decided to investigate the guru's private chambers, previously off-limits to everyone bar himself and a single assistant who alone understood the security. They found treasures of £1.6 million in rupees and 98 kilos in gold, worth almost £3 million at today's prices. But that represented only a small part of his accumulated wealth from what Gethin Chamberlain tartly described as "a lifetime of claiming to be the incarnation of God."
But why single out India? We may be accustomed to drawing a sharp distinction between things spiritual and temporal, between filthy lucre and religious transcendence, but for long as temples have existed they have proved effective as money magnets. Some economic historians argue that organised religion began as a mechanism for collecting and redistributing resources. The gods, like middlemen everywhere, would have taken their cut.
Jesus may have told the rich young man to sell all he had and give it to the poor, but the Christian churches have rarely applied that stricture to themselves. Instead, the wealthy were encouraged to ease their passage through the eye of the needle by giving (or at least leaving) their money to God. It was an offer many kings, aristocrats and bankers felt unable to refuse. Some of the results are currently on show at the British Museum's aptly titled Treasures of Heaven  exhibition. Featured are bejewelled boxes, golden crosses, gilded disembodied limbs and other striking pieces of medieval bling, all designed to contain the saintly bones and other relics that for centuries formed a vital element in popular and elite religion.
As Martina Bagnoli points out in one of the essays in the catalogue accompanying the show, the precious reliquaries were not simply containers of spiritual treasures whose value was unquantifiable, they were also ways of storing up material wealth. In Mainz, a solid gold cross weighing 600lb was made in 983. Bits of it were chopped off and melted down during various emergencies over the following two centuries. By 1161 there was nothing left.
But other sacred treasures have been better preserved, and while no-one has (so far as I know) tried to put a value on every cathedral, artwork, statue and piece of real estate owned by the various parts of the Roman Catholic Church it would surely dwarf even that of the Thiruvananthapuram temple. Or, for that matter, the estimated $30 billion assets of the Utah-based Mormon Church. An even bigger -- and probably impossible -- job would be to establish what proportion of the world's tangible wealth is held by religious organisations of every kind.
After all, it pays to invest for the long term. And you can't get much longer-term than eternity.