IKITSUKI ISLAND, Japan (Reuters) - One by one, the sacred relics -- a medal of the Virgin Mary, a crucifix and other revered objects -- are taken from a cupboard and placed on an altar for a Christmas Eve rite passed down through centuries from Japan's earliest Christians.
Then, kneeling in the simple hall built where martyrs are said to have been burned on this tiny, remote island 400 years ago, five elders murmur chants as they bow and make the sign of the cross.
The kimono-clad deacons are descendants of "Kakure Kirishitan," or Hidden Christians, who kept their religion alive on Ikitsuki and in other isolated pockets of Japan during 250 years of suppression, adapting their rites to the demands of secrecy and blending them with local beliefs.
These days, the religion faces a modern threat of extinction as young people, like those elsewhere in rural Japan, leave their homes in search of jobs, drifting away from their gods and the rituals that honor them.
"It's sad. The tradition of our ancestors is disappearing," said Ayuzo Matsuyama, one of those gathered to observe "Osanmachi" and "Gotanjo" -- Christmas Eve and Christmas -- last weekend, the last Saturday and Sunday before the winter solstice.
"We inherited this 'old Christianity' from our ancestors and we wanted to continue it forever, but young people don't feel that way," added the 79-year-old former maker of sake, or rice wine.
First brought to Japan by Portuguese missionaries in 1549, Christianity was banned a few decades later in 1614, initiating a period of bloody persecution that forced the faithful to choose between martyrdom or hiding their beliefs.
Rites such as confession and communion that could be conducted only by priests were lost. Others took on elements of Buddhist ancestor worship, indigenous Shinto with its focus on purification, and folk practices such as prayers for good crops.
Medals or hanging scrolls depicting saints and martyrs, often with Japanese features, were hidden in cupboards as "nando-gami" ("gods in the closet") and only taken out on special days.
In an apparent echo of the bread and wine of the Eucharist, elders still share sashimi and sake as part of the Christmas Eve and other ceremonies. Huge "mochi" rice cakes adorn the alter.
Transmitted orally and in secret, Latin "oratio" chants, "orasho" in Japanese, lost all but symbolic meaning.
"They preserved the style and form of the Christianity ... that they inherited, but the teachings were no longer from the Bible and changed into respect for local martyrs, so in that sense it can be seen as a Japanese ethnic religion," said Shigeo Nakazono, curator of an island museum who has studied the "Kakure Kirishitan" for years.
When Roman Catholic missionaries returned with the lifting of the ban in 1873, some Japanese Christians accepted their teachings, but others clung to what they saw as the true faith of their fathers.
Matsuyama, who like many of his generation learned "orasho" when he turned 20, admits he doesn't understand the repetitive phrases, some evocative of original Latin or Greek, such as "San Maria" and "anmezusu" (amen), others echoing Buddhist prayers.
"I thought I had to learn it because it had been handed down and it was a kind of memorial for those who died," he said.
The significance of festivals such as Christmas was also transformed into something uniquely Japanese.
"'Gotanjo' is the day of Christ's birth. That's no different from Christianity," said Yasutaka Toriyama, 68, who holds the hereditary position of "gobanyaku," or head of a household that traditionally held a group's relics, such as scrolls or medals.
"But while ours is a religion that believes in Mary and Christ, we also believe that our ancestors who suffered persecution are gods."
Most modern Japanese take a relaxed attitude toward religion, opting for Christian or Shinto weddings, Buddhist funerals and occasional visits to a shrine in between.
Less than one percent of the population are Christian.
How many "Kakure Kirishitan" remain is uncertain, but clearly their numbers on Ikitsuki are shrinking as the overall population of the island, now about 7,000, dwindles and ages.
Nakazono estimates about 500 people in six groups are active practitioners on Ikitsuki, down from about some 2,000 in 20 groups two decades ago.
"About 10 years ago, the fishing catches started to shrink drastically, many businesses failed and there were no jobs for the young people so they left for the cities," Nakazono said.
"The elderly try to preserve their religion but ... they worry that they cannot protect their gods."
Toriyama's group sees a glimmer of hope in the fact that nine men in their 40s and 50s have recently begun studying "orasho."
Still, for Toriyama himself, the fear that his religion will vanish is real and personal. His son left the island after high school and lives with his wife and child in Fukuoka, three hours away by car. Now 33, he works for a computer-related firm.
"I'd like him to learn the 'orasho' and to come back for the festivals," said Toriyama, sipping sake after completing the prayers for "Osanmachi." "But I haven't asked him yet."
What if the religion dies out? "I will have to apologize to my ancestors who preserved this through hundreds of years of suppression," he said. "I will feel I have failed the gods."
Editing by Mike Miller and Jerry Norton