Yes, by law the church ceremony is optional, but in a sense it is also sufficient, since the minister is the one that signs the marriage license officially making the marriage legal (assuming the correct fees are included when the signed document is submitted.) What I am suggesting is partially about separating that power from a church official, making all of the legal aspects of a marriage seperate from the ceremony itself and the religious official that performs the ceremony. The other aspect is semantic. If you stop calling the legal contract between two people marriage, and call it something else like a domestic partnership or civil union, then eventually, people will stop confusing the legal aspects of it with the religious aspects. (Kind of like in Ursula K. LeGuin's "The Dispossessed" - in that story, the moon on the planet the story takes place on is inhabited by a utopian collective of anarchists, who left their home planet long ago. When they started the colony, they removed all terms about "posession" from their language. The idea being that language changes how you perceive the world, and if you never uter the phrase, "That's mine!" it will change your way of thinking a well.