The union of two people can be made lawful. "Marriage" on the other hand should be the provenance of Religion. In short, civil unions should be permitted under the law (and find that divorce is just as easy or difficult as the law makes it). Marriage, traditionally a "sacrament," should be regulated by the churches -- if your church choses to "bless" the civil union, fine; if it does not, fine too. "Render unto Caesar the things that are Caesar's...."