The Bible teaches that mankind bears the image of God sexually. “So God created man in his own image, in the image of God created he him; male and female created he them” (Gen. 1:27). The attempt therefore to disregard all this in the “recognition” of same sex mirage is not just an act of immorality, but also an act of theological defiance. It is heresy; it is apostasy.
The image of God borne by a man and women together is therefore a creational reality, not dependent in any way on the definitions that a secular state might want to come up with. Marriage exists prior to, and independent of, any determinations by any civil magistrate. The magistrate did not create marriage and therefore has no authority to define it, or recreate it in his own image.
The civil magistrate is a steward, entrusted to guard that which God has determined. In Romans 13, the magistrate is repeatedly identified as God’s “deacon,” God’s servant, entrusted with rewarding righteousness and punishing wrongdoing. He has no authority to invert this, and to define as up what God has named as down.
Now this does not mean that the civil magistrate has nothing to do with the definition of marriage; he does have a solemn responsibility to recognize the way the world is, and to discharge his related obligations accordingly. It works this way.
Because heterosexual unions are fruitful — not inherently fruitless the way same-sex copulations are — they are unions that bear, not only children, but also civic responsibilities and challenges. The issues of property and custody and inheritance are in principle woven into every heterosexual relationship, and are woven into no homosexual relationship. They can be nailed onto the side of a homosexual incident, but that is all. They can be arbitrarily assigned to a homosexual partnership, but do not flow out of the creational nature of that partnership.
If two people go into farming together, with one contributing the fertile ground and the other the seed, there will be questions of responsibility and ownership that grow out of the ground. What shall we do with the 30, 60 and 100 fold? But if two people form a partnership in which they plant pebbles instead of seed, the same kind of issues do not and cannot arise. The magistrate does not have to adjudicate anything with regard to the harvest.