By Rich Barlow/The Boston Globe

If you're a former congregant at Cambridge's Immaculate Conception Church, one of the churches shuttered by the Catholic Archdiocese of Boston, and if you haven't been inside the old place in a while, you'll notice a few changes.

The first half-dozen or so rows of pews are gone, replaced by an open wood floor where married couples and families with baptized infants now do a ritual walk-around. The ornate oak altar table and podium were both hand-carved in Serbia. Oh, and you might not understand all of the prayers at Sunday worship, which now combines English, Serbian, and Church Slavonic, an old language used only in Orthodox liturgy.

It's been almost a millennium since doctrinal differences led to separation of Eastern and Western churches, notably Rome and Constantinople, customarily dated to 1054. In a small show of harmony after that ancient division, St. Sava Serbian Orthodox Church now occupies Immaculate Conception, with the help and good wishes of the former Catholic owners.

"We see this as a big blessing," says the Rev. Aleksandar Vlajkovic, the 38-year-old pastor of St. Sava, which celebrated its first service in its new home on Jan. 1. "All the prayers of our people that started this [Serbian] parish a long time ago, we see they are answered finally. . . . The 1990s were painful years for our Serbian community.

"He's referring to refugees who fled Croatia and Bosnia during the Balkans war. (Former Serbian leader Slobodan Milosevic, the architect of ''ethnic cleansing," was universally judged in the West to be the main demon in that conflict and is on trial for war crimes in The Hague.)

One former Immaculate Conception parishioner is as delighted as the newcomers. "We're thrilled to see the church reopen as a house of worship," says Ellen Watson. "That's such a vital part of the neighborhood. I walk out my front door, and I see it every single day. It was so sad [when] there was no one in there worshipping."

Named for the first archbishop of the Serbian church, St. Sava serves all New England states except Maine, which is a separate parish. Outside Cambridge, the nearest Serbian Orthodox churches are in Montreal and Manhattan. It means a long trek for people such as Maja Ana Grujic Stojkov, who drives an hour and a half to St. Sava from her home in Rhode Island for services. But she has regretted the commute "only once, when I paid a speeding ticket."

"It's getting closer to God," she says of the importance of the church to her. "It's also being able to return something" for life's blessings. Grujic Stojkov volunteered at the church to teach Serbian to parishioners' children and now sings in the choir.

Marija Ilic, president of St. Sava's board, also points out the importance of the church as a cultural center for its Serbian community, many of whose members immigrated to America during and after the Balkan war. The church will host concerts and other artistic demonstrations of Serb culture, she says.

Vlajkovic says the parish was established in 1975, but withered because of a lack of parishioners and priests. It was not until 1992 that it was resurrected in Watertown, when a Greek Orthodox church there agreed to let Serbian worshippers use its premises. (The church didn't have a priest until 1994, when the freshly ordained Vlajkovic agreed to serve; before then, the Serbian bishop in Pittsburgh and a retired priest in New Jersey would visit when they could to preside at worship.)

In 1995, the congregation bought a former office building in Wakefield that could hold only 200 people. The closing of Immaculate Conception offered a site closer to Boston and the majority of worshippers in the small but growing congregation, which numbers about 1,000. (Five hundred turned out for Christmas Eve worship.)

The parish partnered with Ecole Bilingue, The French-American International School of Boston, which rented space in an adjacent building owned by the archdiocese. Together, they bought the 4 1/2 acres and four buildings on the land for $6.2 million.

In addition to leading the early church, Vlajkovic says, St. Sava was a medieval monk. The son of Serbia's ruler, he entered the religious life and later persuaded his father to abdicate and become a monk himself. Among his accomplishments, Sava introduced worship in the Serbian language.

The East-West schism in Christianity did not preclude friendly cooperation when St. Sava's parishioners approached Boston Catholic authorities about buying Immaculate Conception. Vlajkovic says he is grateful the archdiocese allowed them to begin renovations before closing the sale.

"This is the same God we worship," says Grujic Stojkov. "We would like Roman Catholics to believe this is not the end to their church and sacred place. It stays sacred."

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