This another reason why some of us are examining the term "marriage" all together. The states and nation as a whole has basically trademarked and/or copyrighted the terms husband, wife, and marriage by classifying it as a legal set of terms. But the Bible never uses the terms in that light. In actuality the term marriage and wife were Romanist state terms created back around the 11 to 14th century. These terms were carried over into Colonial America by the faithful and devout Pilgrims and Puritans but in this area they carried over a Roman doctrine that is still with us today.
You are correct the law code there is about "legally being married" which in most cases requires a legal certificate through the judicial system for it to be that. However, some issues can arise through the use of the terms which can lead to common law unions. If a couple presents themselves to be husband and wife then in some places, even by Supreme Court Case law, they are legally married. That could then cause a problem.
Furthermore, there are questions about why do those who believe the biblical teachings about "marriage" use a term that no longer reflects that idea? Even in a monogamous marriage there is still the no fault divorce laws that conflict with he Christian doctrine itself and those laws exist in many of the states. Additionally, as the homosexual groups continue to press for their cause the term marriage is becoming more and more so diluted it does not mean anything like what the term gamos and gameo from the original Greek language. In a strong sense to continue translating the Bible with the English term marriage is to use an improper English term.
Thus we are fast approaching the need to retranslate this in our English Bibles to a new or other distinct term so that it truly reflects a biblical idea. For way too many years the laws on divorce, remarriage, and even what is a marriage no longer reflects the biblical idea and thus to keep fighting for a term in the culture that is culturally irrelevant makes little sense to me. Why should a Christian spend years, millions of dollars in time and court fees and lawyers, donations to candidates, and other things of the like to fight for one or two terms that when you actually may get it that term still does not reflect the actual idea either culturally or legally anymore?
Other terms can be used to convey the true sense of the words in Scripture. Even Jesus used other words. In Matt. 19 he used the term "joined" and "one flesh" to convey the idea of a union between a man and woman. The Greek term there is different than the Greek term gamos. Other good English terms are "covenant union," "union," "my man and my woman." In the most literal sense the terms my man and my woman are the exact terms translated into English. The term husband and wife are created terms so to speak. The genitive case of aner and gune simply means a man who is owned by another and a woman who is owned by another, i.e. my man and my woman.
As the years go by the term marriage will become to so diluted that it reflects less and less what the true sense of the Word means biblically. Thus it is wiser for us to begin making efforts to either create or translate the terms into other terms that better reflect what we really mean. Too going this route does not create a huge controversy with the state, maybe even none. The state rarely and hardly ever bothers today those who cohabit with one another. But there is still a problem when the people use terms that are protected by legal code. Certain terms today in this legal climate are set within a protected status. To use those terms sets one up to more conflict than if alternative yet just as biblical terms are used.
