We should not underestimate the power of the interfaith family.

They are described in the Oct. 21 j. article “Marin and Sonoma: more Jews, more intermarriage” as a “challenge” for the Jewish community.

The time has come for the Jewish community to mature. Interfaith families are not a challenge; they are a valued part of the Jewish community. Moreover, we are all Jews by choice. So we dare not ignore any component of the Jewish community — the interfaith family or the “Jewish-Jewish” core.

I would recommend two complementary studies to the Jewish Community Federation survey. We should study and document the huge impact interfaith families are having on all of our Jewish institutions. Likewise, there is little or no comment concerning the commitment levels, practice levels and needs of the Jewish-Jewish families. More than one study over the last decade has indicated that a highly committed core group is driving the Jewish community and that core is intensifying their Jewish commitment.

We should be tracking the effectiveness of the outreach that synagogues, day schools and other Jewish organizations especially designed for interfaith families are having on the success of Jewish community and communal life. We should study the interfaith and Jewish-Jewish commitment level, the level of observance, their affiliation level and their commitment of personal and financial resources.

When approximately 20 to 25 percent of a day-school population is interfaith families, you are talking a commitment of approximately $15,000 to $30,000 a year, based on one and two children in a school. This is a deeper commitment than their Jewish-Jewish counterparts who are unaffiliated or semi-affiliated.

This is not the first time in Jewish history interfaith issues have been present, including the Babylonian exile, which took place from 586 to 539 BCE. There was also a high level of interfaith exploration during the Second Temple period, another time when Jewish creativity and adaptation evolved institutions such as the synagogue and the rabbinate that replaced the temple and the formal priesthood.

Our synagogues and day schools welcome large percentages of interfaith families, and it is no longer to anyone’s surprise that a core group of them participate in the leadership and creative force alongside their Jewish-Jewish counterparts.

Seeking out a Jewish neighborhood is only one of many indicators of Jewishness. People in the post-denominational era appear to seek and make community as they go. Word of mouth and Jewish creativity are powerful forces.

In a recent Reconstructionist High Holy Day service, which was attended by 100 or so people, almost 60 percent were from Marin County and at least 25 percent were interfaith families. They are active and searching for community.

We must explore the deep involvement of the interfaith family. However, we should also study the needs of the Jewish-Jewish core. Our federations and our institutions need to document the percentage of interfaith families who constitute a part of the intense core that supports and guides the vision of our institutions and community. We are one community. There is much good news. There is much need.

Rabbi Henry M. Shreibman is the West Coast director of advancement and outreach at Reconstructionist Rabbinical College.