So, I'm a devout atheist and my fiancé is a verrry Christian-oriented woman. We would have no right to marry then??
There is no one who cannot be defined as some sort of minority based upon some kind of "difference".
Everyone has something "different", be it physical, psychological, philosophical, behavioral, or a combination thereof. Everyone can be discriminated against by someone else at sometime. When it is allowed against "them", then some day it will be allowed against you. All it takes is a small swing in the political pendulum.