For as long as Bahaism has existed, the forebears of Rezvan Tavakkoli have abided by it. And over the generations, since the faith's origin 166 years ago, Mr. Tavakkoli's people have paid the price of their devotion.
They have endured beatings, insults, arrest, vandalism, dismissal from jobs, denial of education and other forms of religious bigotry inflicted by the Iranian Muslims who consider Bahaism an intolerable blasphemy for its belief in a 19th-century prophet and his new revelation emerging from Shiite Islam.
Nothing in this pageant of hatred, however, had quite prepared Mr. Tavakkoli for the present moment. He sat this week in a home a dozen miles outside Washington, a 66-year-old man clad in flannel shirt and cardigan against the January chill, as his younger brother Behrouz awaited the verdict of a secret court in Iran, one of seven Bahai leaders facing a potential death sentence for charges of espionage, propaganda and the all-purpose calumny of ''spreading corruption on earth.''
It somehow matters to Mr. Tavakkoli, it compounds the sensation of impotence, that he is the eldest child of six in his family, the paternal figure, the one with the impulse to protect. ''I am regretting I am here,'' he said in his American living room. ''My hands are tied at this distance.''
As for Behrouz, he was the third child in the household, seven years Rezvan's junior. Even now, graying and balding and equipped with bifocals, Mr. Tavakkoli can easily remember Behrouz as a boy upset that neighbor children would smash birds' nests for sport. He invited them, instead, into his family's home in Shirvan, where he had concocted a way to use a shaft of sunlight, a magnifying glass and a film strip to project a sort of movie onto the wall.
That was such a Bahai thing to do, to trust in humanity's better nature and offer a benign alternative to cruelty. Then again, even in a family of observant Bahais, Behrouz had always struck Mr. Tavakkoli as especially committed to his religion.
The religion, of course, has always been the problem, at least to a great many Persian Shiites. Mr. Tavakkoli grew up with accounts, handed down from his great-grandparents, of attacks against Bahais for their supposed apostasy. ''This is the story of the faith,'' he remembers his parents telling him.
Many times during his childhood, Mr. Tavakkoli recalled, the family home was smeared with dog feces, a way of showing that Bahais were as unclean as animals. In third-grade class, the Shiite boy who shared a bench with Mr. Tavakkoli drew a line across it, threatening to beat him if he crossed it.
When Mr. Tavakkoli was 12, during a period of fervid agitation against Bahais led by a radio preacher, a mob surrounded the family's house. It took a sympathetic Shiite neighbor with a visible firearm to drive off the crowd.
For Mr. Tavakkoli, that incident spoke to a complicated reality. Persecution came and went in spasms. Religious bigotry was a useful tool for unpopular governments or even for bosses or landowners with grievances. But the pressures always lifted, and the first five children in the Tavakkoli family earned college degrees and went into professions -- nursing, civil engineering, sales representative, manager in a government agency.
The balance between acceptance and oppression, fragile though workable, ended 30 years ago with the Islamic Revolution. The five oldest Tavakkoli children all were fired from their jobs; the youngest was barred from attending college. In 1980, all nine members of the National Spiritual Assembly of Iran's Bahais disappeared and were presumed murdered. Eight Bahais elected to replace them were arrested and executed the next year. Months later, six members of the local assembly for Tehran, all Bahais, were killed.
Mr. Tavakkoli was chosen to fill one of the Tehran seats. Under incessant surveillance, he moved from house to house on an almost daily basis. A brother Amin, who had been arrested, fled to Pakistan and ultimately Australia with his family in September 1985. Two months later, Mr. Tavakkoli's wife, Iren, daughter, Ladan, and son, Keyvan, also escaped to Pakistan; they later joined Mrs. Tavakkoli's brother in the United States.
In 2001, after his own arrest and interrogation, after the ransacking of his office, after the confiscation of his car and his books, Mr. Tavakkoli used connections to gain a passport to Abu Dhabi. From there, he went on to the United States to reunite with his wife and children and to learn the particular anguish of survivor guilt.
Behrouz had remained behind in Iran and was ultimately named a member of the Yaran, an unofficial leadership body for Iran's 300,000 Bahais. Security agents arrested and jailed him for four months in 2005. Then, in the spring of 2008, he was arrested and charged along with all seven members of the Yaran.
After several postponements, their trial began on Jan. 12 with the reading of the charges, according to reports that reached the Western news media. The proceedings are expected to resume Feb. 7. A chorus of condemnation from around the world -- the European Union, the United States State Department, Amnesty International -- has done nothing to derail the trial.
Mr. Tavakkoli heard a week or two ago from his sister about a visit she made to Behrouz in prison. She said that he looked old and weak, like he was 80, this boy who showed movies on the wall.
''I'm hoping for the light of justice to shine on the men in power,'' Mr. Tavakkoli said, ''because they say they are people of religion.''
And, if not, then Bahai theology has provided an answer. ''It's the mystery of self-sacrifice,'' he said, ''for the world to have a better future.''
PHOTO: Rezvan Tavakkoli, in Clinton, Md., is awaiting word about his brother, a Bahai leader in Iran who faces a possible death sentence.(PHOTOGRAPH BY JIM LO SCALZO FOR THE NEW YORK TIMES)