BURR RIDGE, Ill. — In his day job, Kersey H. Antia is a psychologist who specializes in panic disorders. In his private life, Mr. Antia dons a long white robe, slips a veil over his face and goes to work as a Zoroastrian priest, performing rituals passed down through a patrilineal chain of priests stretching back to ancient Persia.

After a service for the dead in which priests fed sticks of sandalwood and pinches of frankincense into a blazing urn, Mr. Antia surveyed the Zoroastrian faithful of the Midwest — about 80 people in saris, suits and blue jeans.

“We were once at least 40, 50 million — can you imagine?” said Mr. Antia, senior priest at the fire temple here in suburban Chicago. “At one point we had reached the pinnacle of glory of the Persian Empire and had a beautiful religious philosophy that governed the Persian kings. “Where are we now? Completely wiped out,” he said.

“It pains me to say, in 100 years we won’t have many Zoroastrians.”

There is a palpable panic among Zoroastrians today — not only in the United States, but also around the world — that they are fighting the extinction of their faith, a monotheistic religion that most scholars say is at least 3,000 years old.

Zoroastrianism predates Christianity and Islam, and many historians say it influenced those faiths and cross-fertilized Judaism as well, with its doctrines of one God, a dualistic universe of good and evil and a final day of judgment.

While Zoroastrians once dominated an area stretching from what is now Rome and Greece to India and Russia, their global population has dwindled to 190,000 at most, and perhaps as few as 124,000, according to a survey in 2004 by Fezana Journal, published quarterly by the Federation of Zoroastrian Associations of North America. The number is imprecise because of wildly diverging counts in Iran, once known as Persia — the incubator of the faith.

“Survival has become a community obsession,” said Dina McIntyre, an Indian-American lawyer in Chesapeake, Va., who has written and lectured widely on her religion.

The Zoroastrians’ mobility and adaptability has contributed to their demographic crisis. They assimilate and intermarry, virtually disappearing into their adopted cultures. And since the faith encourages opportunities for women, many Zoroastrian women are working professionals who, like many other professional women, have few children or none.

Despite their shrinking numbers, Zoroastrians — who follow the Prophet Zarathustra (Zoroaster in Greek) — are divided over whether to accept intermarried families and converts and what defines a Zoroastrian. An effort to create a global organizing body fell apart two years ago after some priests accused the organizers of embracing “fake converts” and diluting traditions.

“They feel that the religion is not universal and is ethnic in nature, and that it should be kept within the tribe,” said Jehan Bagli, a retired chemist in Toronto who is a priest, or mobed, and president of the North American Mobed Council, which includes about 100 priests.

“This is a tendency that to me sometimes appears suicidal. And they are prepared to make that sacrifice.”

In South Africa, the last Zoroastrian priest recently died, and there is no one left to officiate at ceremonies, said Rohinton Rivetna, a Zoroastrian leader in Chicago who, with his wife, Roshan, was a principal mover behind the failed effort to organize a global body. But they have not given up.

“We have to be working together if we are going to survive,” Mr. Rivetna said.

Although the collective picture is bleak, most individual Zoroastrians appear to be thriving. They are well-educated and well-traveled professionals, earning incomes that place them in the middle and upper classes of the countries where they or their families settled after leaving their homelands in Iran and India. About 11,000 Zoroastrians live in the United States, 6,000 in Canada, 5,000 in England, 2,700 in Australia and 2,200 in the Persian Gulf nations, according to the Fezana Journal survey.

This is the second major exodus in Zoroastrian history. In Iran, after Muslims rose to power in the seventh century A.D., the Zoroastrian population began to dwindle. Seven boatloads of Zoroastrian refugees fled Iran and landed on the coast of India in 936. Their descendants, known as Parsis, built Mumbai, formerly Bombay, into the world capital of Zoroastrianism.

The Zoroastrian magazine Parsiana publishes charts each month tracking births, deaths and marriages. Leaders fret over the reports from Mumbai, where deaths outnumber births six to one. The intermarriage rate there has risen to about one in three. The picture in North America is more hopeful: about 1.5 births for one death. But the intermarriage rate in North America is now nearly 50 percent.

Soli Dastur, an exuberant priest who lives in Florida, is among the first generation of immigrants who started the trend. Mr. Dastur grew up in a village outside Mumbai, where his father was a priest, the fire temple was the center of town and his whole world was Zoroastrian.

He arrived in Evanston, Ill., in 1960, where he knew of no other Zoroastrians, to attend college on a scholarship provided by one of the Parsi endowments in Mumbai, which have since provided scholarships to many others. He earned a Ph.D., worked as a chemical engineer and married an American Roman Catholic he met on a blind date 40 years ago.

Mr. Dastur is a priest in much demand to perform ceremonies because of his melodic chanting of the prayers. He and his wife, Jo Ann, have two grown daughters. Neither married a Zoroastrian. “They’re good human beings,” Mr. Dastur said.

“That’s more important to me.”

The very tenets of Zoroastrianism could be feeding its demise, many adherents said in interviews. Zoroastrians believe in free will, so in matters of religion they do not believe in compulsion. They do not proselytize. They can pray at home instead of going to a temple. While there are priests, there is no hierarchy to set policy. And their basic doctrine is a universal ethical precept: “good thoughts, good words, good deeds.”

“That’s what I take away from Zoroastrianism,” said Tenaz Dubash, a filmmaker in New York City who is making a documentary about the future of her faith, “that I’m a cerebral, thinking human being, and I need to think for myself.”

Ferzin Patel, who runs a support group for 20 intermarried couples in New York, said that while the Zoroastrians in the group adored their faith and wanted to teach it to their children, they in no way wanted to compel their spouses to convert.

“In the intermarriage group, I don’t think anyone feels that someone should forfeit their religion just for Zoroastrianism,” Ms. Patel said.

Despite, or because of, the high intermarriage rate, some Zoroastrian priests refuse to accept converts or to perform initiation ceremonies for adopted children or the children of intermarried couples, especially when the father is not Zoroastrian. The ban on these practices is far stronger in India and Iran than in North America.

“As soon as you do it, you start diluting your ethnicity, and one generation has an intermarriage, and the next generation has more dilution and the customs become all fuzzy and they eventually disappear,” said Jal N. Birdy, a priest in Corona, Calif., who will not perform weddings of mixed couples.

“That would destroy my community, which is why I won’t do it.”

The North American Mobed Council is so divided on the issue of accepting intermarried spouses and children that it has been unable to take a position, said Mr. Bagli, the council’s president. He supports accepting converts because he said he can find no ban in Zoroastrian texts, but he estimated that as many as 40 percent of the priests in his group were opposed.

The peril and the hope for Zoroastrianism are embodied in a child of the diaspora, Rohena Elavia Ullal, 27, a physical therapist in suburban Chicago.

Ms. Ullal knew from an early age that her parents wanted her to marry another Zoroastrian. Her mother, a former board president of the Chicago temple, helped organize Sunday school classes once a month there, enticing teenagers with weekend sleepovers and roller-skating trips.

The result was a core group of close friends who felt more like cousins, Ms. Ullal said recently over breakfast.

Both of her brothers found mates at Zoroastrian youth congresses, and one is already married. Ms. Ullal stayed on the lookout. “There were so few,” she said.

“I guess you’re lucky if you find somebody. That would be the ideal.”

(Source: The New York Times)