The most common interfaith wedding is between a Christian and a Jew- most often Catholic & Jewish Weddings.
As Christianity traces its roots to Judaism, it is not hard to find common threads, not the least of which are the scriptural quotes, "Love thy neighbor as thyself," and "Do not do unto others that which is hateful to you."
The Jewish tradition is firmly rooted in the theology of a messiah or messianic age which will herald in the redemption of humankind. This is in direct contrast with Christian theology wherein Jesus is the son of G-d and the Messiah.
Millennium of anti-Jewish religious persecution have firmly cemented the need to perpetuate Jewish traditions and rituals. And today, among most Jews- even those who are not ritually observant- the stigma of intermarriage is still a very difficult subject to approach and address.
Still, more than fifty percent of Jewish men and women choose non-Jewish men and women as life partners and soul-mates.