Marriage predates religious sacraments - and manmade civil codes as well.
Wasn't Eve made for Adam by God? Doesn't get more sacramental than that.
Point is, that "marriage" is a word that has historically held meaning well beyond "sexual coupling" or "domestic partner". What we currently have is an attempt to redefine the word to mean nothing more than those two things.
Control of the words meaning is probably not controllable in the face of a Leftist media; however, the religious shouldn't accept that meaning, even if it means adding an adjective, such as Holy or Sacramental. This can be reinforced by rejecting the state's authority over marriage altogether.