"When people of radically different yet connected traditions marry, perhaps they are imaging a new way of viewing life.It may seem disconcerting, but could it not also be a call to greater religious harmony? I would like to offer a few points for reflection based on my 30 years of experience as a priest who has been involved in many interfaith weddings. In fact, the very first wedding I ever performed, over 30 years ago, was a Catholic-Jewish celebration. Not too long ago, it was very uncommon for people to marry outside of their religion. In fact, there was a time when even a marriage between an Irish Catholic and an Italian Catholic was frowned upon. Today it is very common to find our children wanting to marry someone of a different faith.
Whatever tradition children are raised in, hopefully they would be exposed to the other faith and share to some extent in the rituals of that tradition.
This was true also when Catholics married other Christians. Canon Law today requires that the Catholic parties promise that they will not give up their faith due to the marriage and that they will do "what is in their power" to share the Catholic faith with their children.
These words were carefully chosen and mean what they say.
(I fully empathize with my Jewish colleagues on this because it is easy for the Catholic Church, with 1 billion members, to be liberal on this point in comparison to the Jewish community with 15 million.) For the Catholic, the ceremony can take place in a non-religious setting, and a priest is not even required.
It is even possible for the marriage to be done simply by a civil minister, and the church will still recognize it as a valid marriage. While there are some rabbis who will celebrate a joint ceremony, most rabbis of local congregations will not.
But as they do that, they need to know their own identity.