I am often asked about people falling in love who believe in different spiritual realms. The simplest answer is that if others believe differently, that is their choice; one that should not be ridiculed. However sometimes we get so distracted by this "two must become one" thinking that we miss if two separates are even complete as one. In specific religions, people must be cohesive because it is mandatory. It is important not to get hung up on the religious aspect of things unless you are religious. Above all things in the relationship, if having a partner who has a different religion or spiritual belief than you, then from the beginning if this a deal-breaker, please do not bend on this.
It has been my experience in observation and in serving others that ignoring your beliefs for the sake of a relationship usually fails in the end. Mainly because our belief systems are what we pass on to our children and the values of religion in a relationship are all fine and dandy until the inclusion of children. It's important to recognize when you're taking on someone else's values for the sake of the relationship. No one is ever more important than the spiritual connection you have agreed to abide by. If others say it's wrong or different, YOU have to answer spiritually for that, not them, so be careful. Don't let love blind you to think you MUST believe the same...don't accept deal-breakers that will hurt your values. As long as the love you obtain aligns with your spirituality, or omission thereof, and it allows for sustained adherence within a relationship, it is not toxic.