I'm muslim and my husband is hindu. We had a civil marriage and ignored family pressure to have religious ceremonies to be wed. We both to some extent have continued to practice our respective religions as individuals and observed each other's holidays together etc but our daughter is definitely not having a typically religious upbringing. She is being brought up to know that mum and dad are from different faiths and to understand and respect her heritage. We just want her to be a good person is all. She can choose to do whatever she wants spiritually when she is an adult, though we do hope she believes in God and will introduce concepts about God and human morality to her when she is older.
We gave her a name which crosses both cultures and she takes part in family holidays with extended family, but that is about it. If grandparents are praying etc when we visit them, we have no problem with her going and joining in with them but they know better than to start preaching to her or 'teaching' her about religion. We've asked them to direct her to us if she has any questions and we know that they will. They are not domineering or insistent that they should have a say in her religious upbringing in that respect..
Grandparents have suggested holding religious events specifically for her e.g. poojas and naming ceremonies, but we have politely declined and they kind of get the picture that they shouldn't ask again! She's our kid so she's brought up with our rules, no matter what anyone else thinks.
We celebrate Eid, Diwali and Christmas together in our home. We don't have beef, pork or alcohol in the house either and we won't introduce any of these items to her diet, though if she opts to consume them herself outside the house when she's older, neither of us will be particularly fussed about it. We try to balance the amount of exposure she has to each religion so that she doesn't feel 'more muslim' or 'more hindu'. e.g. we have only one symbolic item from each religion on display in the house each so she identifies with both in equal measure; if she has taken part in prayer with my family when we visit, I will make sure she takes part in prayer with his family too.
These all sound like silly little petty things, don't they! lol But I guess it's kind of relevant because it is one way that we try to keep everything in the household 'inclusive' so that noone feels left out, different or marginalised.
I do wonder if things will get trickier as she gets older as people seem to insist that it will, but I doubt it will be anything we won't be able to handle as DH and I have been together 16 years and never encountered a problem except when other people decide to stick their beaks in to our business! We have since learned to politely tell people where to go when they suggest that we are not doing things 'right'. I've been told countless times that my child is just going to be a confused messed up adult, but I know that won't be the case. People are just frightened of what they don't know and what is 'unusual'. I couldn't give less of a crap about unwelcome opinions anymore - previously I used to let them bother me but now I know its better to ignore, live my own life and do what I think is best.
DH and I are on the same page spiritually in that we both think that every faith has its merits and demerits but that being a good person, doing the right thing and having faith in God is all that matters to us. Neither of us thinks there is only one right way of doing things and we both have immense amounts of respect for each other's culture and beliefs, which is why we work as an interfaith family. We are also both very resolute in making sure LO is an 'interfaith child' and not more one than the other, which is why we work as an interfaith family. I think if either of us started pushing for one religion to be of more significance to LO than the other, thats where things would start going wrong, but I am confident that will never happen, simply because we love each other too much not to respect each other and we put the success and togetherness of our little family unit above everything else.