Oh, Ned. I foolishly rushed in where angels fear to tread. Since I've already entangled myself, I might as well pontificate further
But seriously, the issues that I wrote about have been in my mind and in my heart for many years. I think I understand where you're coming from.
Who sets the standards of morality, man's changing culture, nature, or the God of nature?
God, of course. However, in this matter, the comparitive quietness (I prefer this word to 'silence') of Scripture indicates that pragmatic concerns weigh in as well, without denying that God's laws must not be violated in any case.
If indeed Judge Moore did have sex with girls that are underage according to Alabama law (I don't believe he did), then he would have truly broken a legitimate law, as well as committed the sin of fornication. However, a man is presumed innocent until proven guilty. Without incontrovertible evidence or an admission of guilt (an out-of-court settlement moves in this direction), any accusations of sexual harassment or assault must remain mere allegations.
My opinion regarding 'age of consent'
In pre-industrialized societies that were dependent on hunting, agriculture or animal husbandry, having many children was essential for survival. Girls were taught how to cook, keep house and perform chores on the farm, and boys were taught farming, hunting, building, and fighting. People recognized that puberty signalled the coming of readiness to procreate and thus increase the numbers of the tribe. Many societies devised rites of passage to mark the induction of boys into manhood, and ceremonies for the induction of girls into womanhood. These, together with cultural marriage protocols, regulated the act of procreation to control the socially destructive proclivities of man, and to protect children, who were a valuable asset. Marriage was reserved for men and women, not children.
The more culturally advanced societies thus regulated marriage, and often set it up in two stages: bethrothal and the actual marriage, after which consummation was sanctioned.
According to the Code of Justinian posted athttp://thelatinlibrary.com/law/institutes.html
under Section X, Marriage:
"Roman citizens are bound together in lawful matrimony when they are united according to law, the males having attained the age of puberty, and the females a marriageable age, whether they are fathers or sons of a family; but, of the latter, they must first obtain the consent of their parents, in whose power they are."
Comparing this to your source, it appears that when females have attained a marriagable age, they are sexually mature. I believe that the latter is a paraphrase of the former. There is indeed no specified age of consent.
In the place of primitive societies' consensus-based recognition of manhood and womanhood, modern Western countries set a minimum legal age of consent to regulate sexual activity. This seems reasonable to me, and does not appear to contradict God's moral law. Since this legal age must encompass all reasonable estimates of the age of sexual maturity, it cannot be set too low. If you think that the specific age of 15, for example, is arbitrary, I would agree. Laws of this type, in which a number is chosen as a standard, are inherently arbitrary. Nonetheless, in the eyes of God, the law is obligatory to Christians.
The Islamic custom of child brides is another matter. Nature and basic human decency dictate that children be protected from sexual abuse. It is one thing to bethroth children, and another to engage in sexual behavior with prepubescent children under the cover of marriage or religion. Pedophiles deserve to have a millstone hung about their necks, and be cast into the sea!