new york | Like every year, the Keen family will soon festoon their home with Chanukah symbols. They’ll light the menorah, exchange gifts and host a family party with latkes and jelly doughnuts.

And then, in the middle of all of this, the Ann Arbor, Mich., family will switch gears. They’ll go into a separate room and help Jim, the father and husband, decorate his tree, and they’ll give him gifts on Christmas Day.

For Jim, 36, who grew up a churchgoing Methodist, and Bonnie, 36, who grew up a Conservative Jew, the arrangement is part of an ongoing commitment Jim says the couple has “tweaked” to raise their two daughters as Jews.

“We have a Jewish home, and I happen to be a Protestant dad,” he says. When it comes to Christmas, the girls “realize it’s not their religion; it’s mine. It’s like celebrating someone else’s birthday.”

While that arrangement may strike some intermarriage critics as convoluted or simplistic, it reflects a reality of American Jewish life.

Interfaith families are negotiating paths they believe are creating new types of Jewish households. How, exactly, these families are changing American Jewish life culturally and religiously, is the subject of intense debate.

“We haven’t watered down the Jewish population; I’ve bought two new Jews into the world,” Jim says, reflecting a widespread view among intermarried Jews.

Nearly half of the nation’s 5.2 million Jews, some 47 percent, married non-Jews in the past five years, up 4 percent from a decade ago, according to the most recent National Jewish Population Survey. Of all American Jews married today, one-third, or 1.6 million, are wed to non-Jews, according to the study.

The National Jewish Outreach Institute, which promotes bringing uninvolved and disaffected Jews into the community, says if the current intermarriage rate continues, American Jewry soon will be dominated by interfaith couples.

Since demographers discovered in the 1970s that intermarriage was rising, Jews have argued over whether to fight the trend, or embrace intermarried couples and encourage conversion or increased Jewish activity.

“Studies show that families in which there is not a competing religion are more likely to have children who identify as Jewish by religion,” says Sylvia Barack Fishman, a Brandeis University professor who has studied interfaith families.

Barack Fishman, author of a soon-to-be-published book on how interfaith families negotiate the ethnic and religious character of their homes, says that having a Christmas tree in an otherwise Jewish home qualifies as conflicting religious behavior. Still, the predominance of Jewish activity means the family is likely “hedging their bets” that their children will identify as Jews.

Often lost in the facts and figures of the debate are the complexities of interfaith life, especially for those committed to raising a Jewish family.

Dozens of interfaith couples recently penned essays for a contest called Encouraging Jewish Choices run by Interfaithfamily.com, a support network for intermarried seeking a Jewish life. The essays provide insight into some of the challenges faced by these families.

Gary Goldhammer, 37, of Tustin won first prize in the “Raising Jewish Children” category of the contest for his piece, “The Letter,” a missive to his dead father.

Goldhammer was raised in Conservative and Reform synagogues, and years ago he married a Lutheran woman from St. Louis. Before their wedding, his wife, Christine, declared without his prodding that they would raise their children as Jews. They joined a Reconstructionist congregation, United Synagogue in Irvine, and five years ago they had a daughter, Alexandra.

Now Christine produces the synagogue newsletter, Alexandra goes to religious school and the family belongs to a chavurah. The family also observes Shabbat and the major holidays.

In part, Gary says, he is immersing his daughter in Judaism in the hopes “she’ll be less inclined to explore” Christianity.

Meanwhile, he believes Alexandra is Jewish, not because of DNA, as he wrote in his essay, but for her “spirit and belief.”

It took years for Rosemary DiDio Brehm and her husband, Bill, to work out the details of their religious lives, including how to celebrate the holidays.

The Brehms and their two daughters, Stephanie, 16, and Danielle, 15, of Tampa, Fla., belong to Congregation Beth Am, a Reform synagogue. The girls go to Hebrew school and participate in the temple youth group.

The family also belongs to St. Timothy’s Catholic Church, where they Mass.

This month they will decorate their house with Christmas lights and a tree with “non-religious” decorations, as well as Chanukah decorations and a menorah.

Yet her daughters do not try to equate Christmas and Chanukah.

Says Rosemary, “I’m wondering if we’re not an interfaith family, but a multifaith family.”