Before Lisa Fung Berger got married, December was a time for Christmas music, pork won tons and fond memories of family gift exchanges.

Since devoting herself to Jewish husband Phil Berger, the first-generation Chinese-American, 32, has pledged to keep pork out of the house, observe Chanukah and raise the couple's new son, Aaron, as a Jew.

The transformation didn't happen overnight, nor does it ever for those who marry into another culture or religion. In fact, the ordeal can be overwhelming, according to couples who seek guidance from rabbis, ministers and counselors before getting hitched.

Overwhelmed or not, as many as 80 percent of Bay Area Jews marry outside the faith, according to Fred Rosenbaum, director of Lehrhaus Judaica, a Jewish-studies adult school in Berkeley. Demographer Gary Tobin of San Francisco confirms that figure, which represents one of the highest intermarriage rates in the country.

And some area rabbis, adds Rosenbaum, report that up to half their congregants are intermarried.

Aiming to investigate the growing intermarriage phenomenon, Lehrhaus recently received a $66,000 grant from the Walter and Elise Haas Fund to help pay for a three-year study in the Bay Area.

"People are very emotional about [intermarriage], but don't have a lot of facts," Rosenbaum said. With this study, "we are going to illuminate the situation."

Until that happens, the $66,000 question for Bay Area Jewry remains — how to walk the thin line between actively opposing intermarriage, which many view as the biggest threat to Judaism since the Holocaust, and recognize that the survival of diaspora Jewry may depend on raising the children of intermarried couples as Jews.

That predicament is not lost on area Jewish agencies and rabbis, who promote a variety of interfaith programs to encourage interfaith individuals, couples and families to affiliate.

Intermarriage has its primary impact on the liberal movements within Judaism. The Orthodox rarely intermarry, and interfaith couples generally have no place in Orthodox synagogues. Many Jews seeking to marry non-Jews will approach Reform rabbis, some of whom will perform the ceremony.

When the Bergers began to talk marriage, it was Lisa who sought out the Reform Congregation Emanu-El's Introduction to Judaism class and interfaith discussion group. Phil, now 37, attended both with her.

"When I met my husband, he made it clear that he wanted to raise the kids Jewish," said Lisa, who grew up with no religion.

"We had been dating two weeks," Phil recalled, "She said fine. It was a lot easier throwing yourself into a relationship knowing there was not this hurdle."

Phil said he welcomes his wife's culture in the couple's San Francisco home, and now muses over the cultural contradictions in his own upbringing. His mother was raised Orthodox, his father Reform. They compromised and made their home in the Conservative movement.

As a new dad, Phil says he is predisposed to uphold tradition because it's up to him to teach his family about the joys of Jewish observance.

At Emanu-El, Lisa learned about Jewish holiday and Shabbat observances. She began to attend services with her fiancé and talked with other interfaith couples.

The couple found that the group discussions helped them to identify their differences.

"There were times that the group [of six couples] was so personal…Couples would argue right there until they were done," Lisa said.

Emanu-El's Rabbi Helen Cohn and Rosanne Levitt, an interfaith counselor, moderate the discussion groups to help couples reconcile their issues before getting married, and to help the already married cope better.

Levitt also is the director of the S.F.-based Interfaith Connection, one of the oldest and most comprehensive interfaith programs in the country. Based at the Jewish Community Center of San Francisco, the program offers classes on holiday celebrations, a discussion series on the common issues of interfaith contention, and a regular panel of interfaith experts and couples.

At Emanu-El, many students of Levitt and Cohn decide to convert. Some students ask Cohn to marry them. Still others form interfaith chavurot and join the synagogue. In all, about 75 percent of the discussion group participants stay involved with synagogue life.

"Older congregants are rather glad on this issue," Cohn said. "There's a sense of perpetuating Judaism."

Area Conservative congregations also welcome the intermarried. But while some Reform synagogues may allow a non-Jew to recite a blessing on the bimah and all will accept a child of patrilineal Jewish descent as a Jew, Conservative synagogues do not. Moreover, Conservative rabbis are prohibited from marrying interfaith couples unless the non-Jewish partner converts.

At Congregation Kol Shofar in Tiburon, Rabbi Lavey Derby explains that such restrictions have not discouraged about 40 interfaith couples at his synagogue from coming to services or participating in adult education classes and the congregation's interfaith chavurah.

"We have invited all interfaith couples to become active in the synagogue," he said, though he acknowledged that some non-Jews may be uncomfortable with the limitations on their level of involvement.

In addition to local synagogue programs, the regional Union of American Hebrew Congregations, which represents Reform synagogues, also offers local interfaith programs such as synagogue how-to courses, Couples' workshops and social events. Most of the programs are designed to encourage Jewish choices and affiliation, said Linda Walker, a program director at the S.F.-based UAHC office.

Most recently, the UAHC hosted a national program, "Taste of Judaism," which aimed to give both non-Jewish spouses and Jews who were not raised with Judaism an overview of what synagogue life is all about.

At nine congregations, 566 people from all over the Bay Area participated in "Taste of Judaism." Of those, 223 were interfaith couples. Walker considers the program a success; 18 percent of all participants affiliated, 33 percent enrolled in synagogue classes and 14 percent became interested in conversion, she said.

Listings of new and other ongoing interfaith programs throughout the greater Bay Area can be found in an interfaith newsletter called Bridges, published three times a year by the S.F.-based Jewish Community Federation.

No formal study tracks interfaith couples after they complete interfaith programs, according to Levitt, so it is not known exactly how many go on to affiliate. But, she added, the results of the Lehrhaus intermarriage project may offer insights on how to evaluate and design future programs.

Rather than compiling statistics, the project will broaden Lehrhaus' program of interfaith classes at a dozen sites throughout the Bay Area on such topics as the history of intermarriage and Jewish perspectives on Jesus, as well as the ever-popular couples' workshops.

As part of the project, Rosenbaum also plans to survey rabbis and others who work with interfaith couples and families. At the end of the three years, Lehrhaus will host a national conference on intermarriage in San Francisco.

While the study itself won't alter intermarriage in the Bay Area, its findings could lead to a national model of how to preserve American Jewry in the face of intermarriage, Rosenbaum said.

Meanwhile, families such as the Bergers will continue to grapple with making a happy marriage of two cultures. After several years of observance, Lisa now looks forward to Jewish holidays. But she still doesn't know how she will respond when her children ask about Santa Claus.

Phil hopes that son Aaron will learn to speak Cantonese as well as Hebrew. He plans to raise him among the children of other interfaith couples he has met.

"This is the first baby of eight couples. Now he has all these aunts and uncles in this interfaith chavurah. All but one couple are going to raise their children as Jews.

"It would be very easy for all these couples to be nothing religiously. But the non-Jewish spouses," he quipped, "are really gung-ho."