"as it was in the beginning is now and will be forever."  Humanity (being created) does not controll the creator. If he was controllable, that would be a god I would've t want to believe in.  What we have morphed into does not translate into what god now accepts. 

Regarding the word "marriage" being biblical. Many concepts we believe to be truthful, accepted by society and happen to be biblical at the same time are not necessarily spelled out in the bible.