[Always *]

I think it entirely depends on a number of things.

For example how devout are you two? Does he eat pork (or not), attend synagogue all the time, and celebrate holidays, and do you do the same for Christianity? Are you willing to attend synagogue with him periodically and him attend church? I don't think you guys necessarily have to participate in the others religion, but I do think that you guys have to be open to and willing to engage in both religions event if you're keeping it at arms length. For example, you can't ask him to like leave his Jewishness at home and but then expect him to be totally into you wearing a cross and having him come to church or something. And the balance is to not exclude both of your religions from the relationship because that'll just create problems if your faith has to be stifled in a significant part of your life. I think that, however you guys decide to go about it, that you need to celebrate both of your religions even it is is to say "I don't believe this, but I want to support you in growing within your religion".

Another factor is family; will your parents put pressure on you not to marry him or even to end it now just because he's a Jew? will they ever come around and change their minds? This can be a lot of pressure to put on to young people and maybe you guys can rise above it, but it could put a lot of strain on the relationship.

I definitely think that things can work out because, fortunately, as humans, we are multi-dimensional beings and your religions don't have to be the thing you build your lives on. For example, I'm not a religious person. It's not to say I don't have a religion, I'm just not practicing. My partner and I aren't religious in our relationship; we built our relationship around other things such as our love for the outdoors, music, and books. I think you can treat religion as something like football; you don't necessarily have to want to watch football or get excited about it, but you can be happy for your boyfriend when he goes and watches football, even if it is in your living room, and when he and his friends are excited about football you can smile and let it be (now swap all of that for him being Jewish).

I hope this helps