Perhaps you have been reading, like I have, the details of the bitter tug-of-war that a little three year old girl is going through because of a divorce. Custody isn't the issue. Religion is, as it is so many times. Seems the mother is Jewish, the father Jewish by conversion but Roman Catholic by birth. The father made a commitment to raise their small daughter as a Jew, but since the divorce he has introduced her to the Catholic church and, as I understand it, even had her baptized (although one report said she merely had watched a baptism). The issue is in the courts right now.
As one whose life has been touch by the pain of a divorce and a subsequent religious issue of a different but equally distressing alteration in beliefs, I find myself wishing I could shake that father until his teeth rattle. Reneging on a commitment as a way to get back at an ex-spouse is, in my book, pretty low down, and involving a child in it puts it right in the gutter.
I remember reading a really good article that I think embraces the best of multi-religious families and how religions can work together when people put love of family, especially with their children, ahead of piety and ritual. The circumstances are different to begin with, but the illustration of religion in a mixed marriage is a glowing testament of what minds governed by love and not hate can do.
Take a read at this young man's essay: http://reformjudaismmag.org/Articles/index.cfm?id=1289