[Same sex] marriages are a sort of legal fiction which we must respect.He thinks there is an essence to marriage that resists legal re-definitions, just as horses and chairs could not be re-defined. This shows a curious blindness to the complexity of social institutions, which, by their very nature (one may say 'essence'), are defined by their social milieu. Simply perusing the Wikipedia article on marriage presents a bewildering variety of types, many of which do not feature just one man and one woman (WLC's preferred flavour). Of course, to describe the marriage of two people in love as any sort of fiction is deeply offensive to those involved.
The Supreme Court did not legalize, nor is anyone advocating for, gay marriage. What it legalized was same-sex marriage, regardless of sexual orientation....and he is right, strictly speaking. But let's not pretend that Craig is railing against two heterosexual men getting married; it is the homosexuality he is prejudiced against, and his language shows his prejudice:
Suppose you are a baker who is approached to make a wedding cake for a same-sex wedding or that you are a wedding photographer who is hired to photograph a same-sex ceremony. It’s hard to see how you can justifiably resist legal authority here and refuse to comply, regardless of how distasteful it may be to you, since your activity is not sin on your part.Craig supposes it may be 'distasteful' to provide a service for a same-sex marriage; why 'distasteful'? Sin is not a matter of taste, after all. Plainly it's the homosexuality that is not to Craig's taste, rather than some contravention of his definition of marriage. If somebody redefined a horse as a chair, no-one would find that 'distasteful'; simply incorrect.
As for government authority, he says:
...we should and must resist authority if it requires us to act contrary to God’s will.So, he thinks it's necessary for Christians to impose God's will over and above the law of the land. As at least one study suggests, what God wants tends to be the same as what the individual believer wants. This is a recipe for insurrection, or at least civil disobedience à la Kim Davis, even if one has some sympathy for conscientious objectors in general.
It's nice to see that Craig can see the way the wind is blowing, though:
As our secular culture becomes more and more accommodating to same-sex marriage, the pressure upon Christians to compromise and conform will be heavy and unrelenting.Yes, the repeal of anti-miscegenation laws delivered legal justice and, as a consequence, generated social pressure on racists to drop their prejudices; so too, now, will the pressure build upon the homophobic to drop their prejudices now that equality before the law has been granted to those of every sexual orientation.
Craig's response reveals the problem with a morality embedded in the aspic of ancient mores; they give the prejudiced ammunition in their fight against overwhelming reason and evidence. Just as many sensible practices and beliefs have arisen through our genetic and cultural history, so too has prejudice. We need the freedom to challenge our practices and beliefs to sort the sensible from the insensible, and religion, amongst other things, hinders that process.