Many people who do not share the same spirituality can (and, do) get along quite well, as long as one's beliefs are not the subject of ridicule. For me, I opted to choose a partner who believed in the same principles, not necessarily religion. But, the most important part of the spirituality that we share is that it is based upon respect, not ridicule or degradation.
Any passing jokes or "harmless" ridicule against another person's beliefs, race, gender, sexual orientation, etc., would be a red flag for me.