I know, we have a mixed marriage here, too. Since I don't spend much time and energy thinking about what happens to me after I die, it isn't important to me that DH holds a different internalized value than I do. He doesn't seem to be concerned that I will not be joining him in The Next Life. We don't talk about it, we are very much centered in the Now and in the immediate future.
I thin k some people wonder 'how can you live with someone who holds such a radically different basic value?' but this issue just doesn't come up in my married life. We have talked about choices for funerals and body disposals upon death, but when it comes to the spirit, I guess we consider each other out there on our own.