Intermarriage in the UK is broadly stable at just over a quarter of the Jewish population and those that marry non-Jews are less likely to bring up their children as Jewish than those that marry Jews.
These are the headline findings of the JPR Report on Intermarriage published last week . So far, so good, but then the trouble starts. The report does not, nor can it from the data, tell us why this is happening and the risk is that we draw diametrically the wrong conclusion.
The Jewish community in Britain divides between those that choose to opt out of the wider world and those who choose to integrate with it. For those that choose the latter route, from secular to mainstream orthodox, we regularly interact with non-Jews and inevitably from time to time fall in love and want to marry them.
The first mistake is to conclude that this in itself diminishes our commitment to our Judaism. It may of course be evidence of a lack of interest, but in my experience it is what happens next that is more likely to determine whether the family becomes estranged from our community or an integral part of it.
Last weekend, I was interviewed along with orthodox Rabbi, Dovid Lewis, about the JPR report. He explained the principle of matrilineality and argued that Torah prevented the children of mixed marriages with Jewish fathers from being regarded as Jewish. He went on to argue that the Torah promoted "marriage within the [Jewish] family."
And yet the Torah provides plenty of examples of men - not least Moses and Joseph - who married outside the tribe. And Ruth, an ancestor of David, is born a Moabite. It is not the Torah that determines matrilineality, but the Rabbis, human beings even if divinely inspired, who interpret and maintain it, regarding who is a Jew and the laws around marriage. The attitude that we adopt to those that intermarry is, therefore, much less a matter of "law" than "lore".
The trouble with a lore that frowns on intermarriage is that, however good the intentions of those who claim all should nonetheless be made to feel welcome within our communities, such families do not feel included. When the children are not recognised as Jewish, or even, if they are, their parents' relationship is described in terms of marrying "out", the message of rejection, intentional or not, could not be clearer.
In such circumstances is it little wonder that many intermarried couples consider themselves not to be welcome, and their children to be second-class citizens, if they are "citizens" at all?
As with the JPR's previous report - on which we congratulated ourselves for arresting the decline in the number of Jews in the UK - the true story is hidden in the detail.
Intermarriage rates are only "stable" because of the phenomenal growth of the Charedi community.
Amongst mainstream Jewry the same data shows that intermarriage continues to climb and the message "must marry in" is not working. For us, even if it were, it would be misjudged. "Must marry in" is not only unachievable, it is undesirable.
The vast majority of Liberal Judaism's 40 communities are outside London and North Manchester. In almost all these areas, the majority of members are in, or the product of, intermarriage. By welcoming and including all, on an equal basis, by not seeking to pass judgment or delineate, there are now thriving Jewish communities in Lincoln and Leicester, Suffolk and Stevenage, Gloucester, Hereford and York.
In such communities and a dozen others, both parents - Jew and non-Jew - are often equally involved and as a result their children grow up to feel welcome as part of the community.
If we want Jews to play a full part in the wider world, intermarriage is not only inevitable, but it can be a blessing rather than a curse. Our attitude to it is what is making Liberal Judaism the fastest growing formal denomination in the UK.
We all agree that Judaism provides a phenomenal way to live life: rituals to enhance life and community to support it. The challenge is to create an environment in which as wide a group as possible are able to participate in Jewish communal life.
The real message of this research is not "thank goodness more are not marrying out", but "everyone can be marrying in, if we welcome them with outstretched arms and an open heart."