An influential and outspoken Vatican official told a Catholic group in Pittsburgh that if bishops, priests and sisters show a joyful commitment to traditional faith, young people will become priest and nuns.

"If you have a bishop who is no-nonsense ... a bishop who is transparently joyful in the priesthood, there will be seminarians," Cardinal Francis Arinze said to applause from 625 members of Serra International, a lay group that promotes vocations to the priesthood and religious communities.

Serrans from 18 countries are meeting at the Pittsburgh Hilton and Towers. They are named for Blessed Junipero Serra, the 18th century Franciscan who pioneered the California coast to evangelize Indians.

Arinze, 71, a Nigerian who runs the Vatican office on liturgy, is on many lists of possible future popes. A traditionalist, he is noted for a sense of humor coupled with a sharp candor.

"It is not true that young people of today are allergic to a life of sacrifice. But they want to be convinced why they should sacrifice marriage and earthly goods and give up doing their own will. Above all, they want to see people who are role models," Arinze said yesterday.

"Young women do not want to join a group of old women who seem to be confused [about their mission]. Young men do not want to join a diocese where the priests seem to be angry."

He compared nuns who did not want to wear religious garb to a flight attendant for Alitalia who wanted to wear the uniform of American Airlines. "What do you think Alitalia is going to say? Let's dialogue?" he asked, to laughter from his audience.

He defended celibacy, rejecting arguments that in some cultures men without wives or children are not respected.

"The gospel is a challenge for every culture. ... There is no part of the world where the gospel is sweet and easy," he said.

Decisions by Catholics to have few children have meant fewer priests, he said. Parents discourage priesthood and sisterhood because they want grandchildren or need grown children to support them, he said. He suggested that many potential priests "have been aborted."

Arinze noted that churches with married clergy also have a shortage. He spoke as Bishop Donald Wuerl of Pittsburgh prepared to ordain four priests today.

"They are really terrific young men. And how appropriate to have an ordination in the middle of a Serran convention," Wuerl said.

Wuerl was upbeat, saying that more than 60 high school and college students recently attended a cook-out he held for prospective seminarians.