Government has as much right to the word as religions, it's not like religions invented marriages. The catholic church, for instance, only took over marriage during the middle ages. Historically,

> marriage vows did not have to be exchanged in a church, nor was a priest's presence required. A couple could exchange consent anywhere, anytime.

For the first quarter of the common era, the church was split between trying to get the church involved in marriages (e.g. Tertullian recommending that christians "request marriage from their priest") and recommending eternal celibacy and virginity. Augustine and Isodore of Seville developed the sacramentality of Christian marriage (Augustine at least still taught that virginity remained superior).

The official catholic declaration of marriage as a sacrament (and thus declaration of the takeover) was actually political: it was made at the Council of Verona in 1184 as part of the case against Cathars, who held that marriage and procreation were evil.

The case for marriage belonging to religions is "it's been that way for as long as I've lived". Previously in that category: slavery, illegal abortions, children labour and lots of other awesome company.

You hit the nail on the head with marriage definitions.

A bigger problem, not admitted by the religious side of this debate, is that the legal definition of marriage is what grants many states rights. To some extent that some states would have to rewrite their constitutions to no longer honor marriage as an institution.

I don't think the end game legally would end very well for the people stating that "marriage" is a religious term. It might be in common speech, but given we're talking about granting legal rights its about as relevant as ice cubes to an eskimo. Push this matter too hard and its likely that marriage as a legal term or definition goes away entirely.

I'm all for it but pushing the religious points too far will only cause more issues for those fighting via that angle. (no i'm not a lawyer)