The beat of the congas thundered through the basement as the priestess called out to the spirits, praying to the orishas. It was hot that day in her Chicago home, and the backroom was crammed with people dressed in white. They had come for the sacred initiation ceremony into the Lukumi religion, also known as Santeria.

The two people being brought into the faith were dressed in satin, their heads shaved and covered with vibrant splashes of paint. Soon, the slap of the drums got faster. The priestess, Asabi Thomas, closed her eyes, moved her round body and sang louder. Sweat dripped down faces as the crowd chanted in the Yoruban language, dancing and clapping, transforming the Chicago basement into the African village that is the soul of Santeria.

"We're taking them through a life-and-death process," Thomas said later. "They have become new people today. They are starting a new life with the orisha as their core foundation. Today is a happy day, and we're having a big party."

Rarely seen by outsiders, the initiation rituals provide a window into the power, beauty and mystery surrounding Santeria. From the backrooms of botanicas and sacred basement shrines, the faith is moving into the religious and cultural mainstream.

In Chicago and elsewhere, religious scholars as well as followers see Lukumi growing not only among longtime devotees who are of Cuban and Puerto Rican descent, but also among African Americans, Mexicans and white Midwesterners.

Thomas and the others who gathered for the initiation, most of them young blacks from the Midwest, said they embrace the religion as a bridge to their African past. Others say they find spiritual fulfillment in the religion's consultations, which focus on personal problems and provide resolutions through the orishas, or spirits.

Today, museums display exhibits about botanicas, the spiritual shops that supply herbs and other materials for rituals. High priests, known as babalawos, lecture at universities, and a popular Cuban hip-hop group known as Orishas raps about Santeria. Recently, Chicago White Sox manager Ozzie Guillen said he also practices the religion.

New Lukumi leaders, such as Thomas, seek to educate followers about the religion through shops and religious seminars. Several leaders have registered their houses of worship as nonprofit organizations, another step toward legitimizing the faith.

But the move toward greater openness has not come without controversy, as shown by the concern among some leaders over the religion's growing presence on the Internet. Some see the hundreds of Web sites that have emerged as a powerful tool for connecting the community as well as dispelling prejudice about the religion and its misunderstood ritual of animal sacrifice. Others argue that the sites provide a forum for frauds not devoted to the true faith.

"The religion has grown beyond the control of the elders who originally transmitted it," said Joseph M. Murphy, a Georgetown University theology professor and author of "Santeria: African Spirits in America."

"There is so much information out there that anyone can represent the tradition in his or her own way. So it's very difficult to determine what might be older traditional knowledge from what might be innovation."

The roots of Santeria trace to West Africa among the Yoruban people in the region now known as Nigeria. The basis of the faith is the powerful orishas, believed to watch over every force of nature and all aspects of life.

From the 16th to 19th centuries, thousands of Yorubas were transported to Cuba, enslaved and forced by Spanish colonists to convert to Roman Catholicism. The Yoruban people in Cuba eventually came to be known as Lukumi, which means "friend" in the Yoruban language.

In a fight for religious survival, the Lukumi assigned a Catholic saint to each orisha so that slave owners would think they had been converted. Saint Barbara, for example, became the Catholic face of Shango, the orisha of thunder. The religion became known as Santeria, the way of the saints.

After the 1959 Cuban revolution, babalawos and priests known as santeros and other Lukumi followers immigrated to Miami, New York, New Jersey, Chicago and Puerto Rico as pioneers of the religion in the United States. Since then, thousands have been initiated. Researchers estimate that at least 50,000 people practice the faith in the United States and 2 million worldwide.

Hector Rodriguez, one of the first babalawos in Chicago, still commands a powerful presence in the community. Rodriguez immigrated to the United States in the late 1960s from Matanzas, Cuba. To his followers, he is a priest, psychiatrist, holy man and healer.

As a respected elder, Rodriguez, 67, practices Ifa, the spiritual divination system used to consult the orishas. Hundreds across Chicago come to Rodriguez seeking help for health problems and financial difficulties. A consultation costs $40.

Rodriguez discovered his spiritual gift as a young babalawo in the 1970s, when a woman came to him with pains in her body. He asked her to lie on the floor, placed a bird on each of her shoulders and began to recite Yoruban prayers as he had been taught.

Soon, he said, one of the birds fell dead and the woman's body began to tremble uncontrollably. Rodriguez became nervous and asked the woman whether she was all right. Within minutes, she stopped shaking and stood up, saying she was fine.

"That was frightening, but that was when I knew I had something," Rodriguez said. "I had some kind of strange power in this religion."

A visit with Thomas contradicts any notion that the faith is a primitive one. From her bungalow, Thomas, 52, keeps in touch with most of her godchildren by e-mail from her laptop or by cell phone. "Godchild" is the loving term for one who has been initiated into the faith, similar to baptism by godparents in the Catholic Church. Thomas has 16 godchildren in all.

Born and raised in Chicago as a Catholic, Thomas has formed one of the largest and most respected Lukumi houses in the Midwest, with nearly 100 followers. She is known for an annual lakefront ceremony for Yemaya, orisha of the water. This summer, 50 people gathered on a beach before sunrise, filled a small boat with offerings of flowers and fruit, and cast the vessel upon the water.

"We want to demystify the religion and get rid of the wrong perceptions so people understand this is just another way of worshiping God," Thomas said.

During a sunrise ceremony honoring the spirit of water, Santeria practitioners cleanse themselves in Lake Michigan. Fifty people gathered, filled a small boat with offerings of flowers and fruit, and set the vessel free.To his followers, Hector Rodriguez, a "babalawo" in Chicago, is a priest, psychiatrist, holy man and healer.