There are different races...cultures...socio-economic statuses, and perspectives, religions, skin complexions, hobbies, political viewpoints...oh the list could go on for so long. Frankly, race probably belongs low-to-middling in importance.
Of course, what trumps it all is being led by the Spirit, and in receiving the "holy yes" before we join together in holy matrimony.
"Power tends to corrupt, and absolute power corrupts absolutely." -- Lord Acton