Thanks for this article, which I find excellent and agree with almost entirely.
I would like to dig just a little more deeply into the quote I’ve highlighted. While I agree with your stated reasoning, I would go a little further.
“Marriage is a whole lot more than …” is a privileged statement of power. Underlying the statement is the assumption that “more" means those elements that Christians consider to be spiritual components of marriage.
By making that argument, the author implicitely asserts a Christian right to define marriage on religious grounds.
But as I have often argued in the past, the concept of civil marriage long predates Christianity and has existed across human cultures even in places where Christianity has never existed as an important cultural force.
By insisting civil marriage ought to rest on Christian foundations, Christians assert not just power but demand supremacy over those with different religious beliefs or no religious beliefs.
This is deeply problematic in a pluralistic society that extends the promise of liberty to all.
It seems problematic also to Christian ideals of non-judgment and tolerance. I doubt Jesus was highly invested in defining civil institutions or settling them on religious foundations.
His message seemed to focus on a much higher order of spiritual affairs.