here are three domains here which are intersecting much more heavily than they have reason to.
One is the domain comprising all our baked, half-baked, and completely gooey raw postulates and assumptions about the spiritual aspect of existing. Some put God in there, others put wood-sprites and naiads and thunder-gods.
The second is the domain of moral judgments about right action, wrong action and "don't care" action weighed in our many different scales of goodness and badness. People often conflate these two, asserting that God dictates their moral choices, which is tricky, but their business.
The third is the civil domain where the dynamics of how we are to live with each other naturally fall. Every law and regulation governing personal liberty, personal obligation to the community, obligations among groups within the nation, transactions among states, individuals and corporations, fundamental rights, what shall be subjected to rules and what shall not be, fall here.
It is madness to inject godhead (zone 1) into civic regulation, a lesson we learned in the centuries prior top 1750. Despite this lesson, Porposition 8 in California wa slargely defended by some on "spiritual" grounds; I would argue the word received serious abuse in this context.
Defining right and wrong actions (the nature of moral judgements) based on godhead is one step away from that madness, but still very much in the color of it. To allow ancient codes and decrees to dictate to you what is right or wroing, regardless of what you see and think for yourself, is to subordinate your ability to know to an authority not closely linked to your own experience--even if it is a parent. This means you are committing yourself to adulterating your own integrity in order to get along with an authority, a slippery slope indeed.
Injecting zone 2 into zone 3 is probably inescapable, since people want to live under laws they believe or moral. It is unfortunate that the difference between authroitarian moral decrees and moral/ethical decision based on live thinking attention are not differentiated among, but they aren't. Regardless, the remedy we have evolved in our country is to require a coherent framework of ideals with which all regulations should align, called the Constitution. One of the key precepts of such a system is to leave to individual decision those powers that do not actually have to be centralized for the public good. Likewise, the Consittution specifically leaves to the States jurisdictions not named as belonging to the Federal government. The principle of leaving such decisions to the lowest level at which they can be made is a very wise one, because, by its nature, it maximizes the self-determination of individuals in States, and of States in a Federation.
When citizens are unwilling to allow others to exercise free choice in one or another subject, the first question that has to be asked is whether public harm (rather than moral appropbation) is being caused. That is why anti-miscegenation laws are now dead, and absurd. No actual public harm. Similarly, there is no public harm in letting women vote as equals, or in requiring equal rights among citizens of different colors. There is hterefore no grounds for a State to ge tinvolved with them under the principle mentioned above.
There is no public harm, either, in two people receiving legal., civic recognition of their intention to become a couple under the law, regardless of their color OR their sexual orientation OR their religion OR their income OR their breakfast cereal. It is an unconscionable reversal of the best of our Great American Experiment in freedom to decree that their is, and a sorry manifestation of either ignorance, confusion, or ill-will on the part of those who have confused these three distinct domains with their ill-considered votes.