To your response:
The Reasonable Faith site is refreshingly even-handed, but the essay you have directed me to is not helpful, nor is it's argument what I would call "solid". Paraphrased, it proposes a dichotomy between a purely "subjective" morality and a "truly objective" morality, with the "subjective" morality being the best that an atheistic worldview can offer, and then uses that as a foundation to argue that an "objective" morality cannot be weaseled out of or subverted, while a "subjective" morality cannot be used to deter corruption, greed, and selfishness, therefore an objective morality is superior, therefore an agent capable of establishing an objective morality is preferable, therefore we should believe in God (whether or not one exists). (It claims to "not be about" that last part, but halfway through, it dives right in to making that very case.)
Unfortunately the dichotomy upon which the whole argument hinges is severely flawed.
First, regarding "subjective morality", it assumes that a morality that "merely" evolves as a group survival tactic for humans is not fit for the governing of humans. To quote an example: "It is not biologically or socially advantageous and so in the course of human evolution has become taboo; but there is on the atheistic view nothing really wrong about committing incest." However, the requisite objection is right there in the description: It is not biologically or socially advantageous; in fact, it is biologically and socially damaging. That is enough to justify its establishment as a taboo to humans, and enough to explain the passing of laws and inspire the direct intervention of humans into the affairs of other humans, in matters of incest. But the essay demands more, as if humans need something more than, "It is bad for me, it is bad for you, it is bad for us, for clearly documented biological and social reasons." It has by this point already constructed its fallacious requirement for an "objective value" beyond the purview of humans, and is now sounding the alarm. And its basis for this? Why, unless humans are provided with it, they will disregard the objections and engage in the damaging behavior anyway. They will convince themselves that greed, corruption, and selfishness are acceptable, because after all, "it's all relative". This is a variation on the old "left to their own devices, humans are evil" trope that I mentioned before. It's just not that simple.
Now let's change gears and consider William Craig's "objective morality" - the other side of the dichotomy. He assumes that such a morality must exist as a template towards which we, as humans, must strive, for if there were no meta-human template, we would just be paddling in metaphorical circles. This assumption has two major flaws.
First, it disregards the well-explored philosophical phenomenon that there does not have to be an objective template for a class of objects, for humans to still recognize members of that class. The most common example given is that of a chair. Nowhere in history has there ever existed an objectively precise "perfect" example of a chair. And yet humans still have no trouble walking into a room and recognizing which objects are chairs, and which are not. This is because of two conditions: First, the essence of a chair is in its suitability for a particular purpose, and second, that purpose is one naturally understood by those who need to recognize chairs (because humans sit, and humans quickly realize what is good for sitting on and what isn't). These two conditions can also be applied, without difficulty, to morality. There is no need for an objective template, even an unobservable one.
The second major flaw with an objective morality is, it begs the question of why one is necessary. That is, to be useful as a philosophical tool, it requires that it be apart from the morality of everyday humans, establishing a situation where humans are enacting a struggle towards or away from it. But it does nothing to explain WHY this situation would be so. Why not, instead, have that One True Objective Morality planted within humans at birth? Why leave any room for doubt?
No reason is given. Instead, it simply assumes the current circumstance, because it must, and argues from there. There have been many imaginative scenarios spun about why humans would be deliberately designed to struggle, in the face of an assumed meta-human objective morality, but none of them constitute or present useful evidence FOR that objective morality. They assume it is so. To assume otherwise would be counterproductive - it would undermine the power of their faith. (And, coincidentally "left to their own devices, humans are evil (or at best morally neutral)" is often their central premise. One popular scenario is a "struggle" between "god" and "satan".)
Instead, even William Craig's essay must content itself with merely arguing that the struggle towards objective morality - the struggle itself, not any particular content of the morality - is preferable to a struggle with a "subjective morality" contained in other humans and the world at large.
If one accepts that we live in a complex world where morals can conflict, and observes that many social situations require a certain amount of learning and wisdom before we can make informed moral judgements about them, and combines that with the fact that groups can sometimes work at cross-purposes to their individual members, then it becomes obvious why humans would struggle with morality: Because living morally, living the "right" way, IS A STRUGGLE. The real world presents difficult situations that must be navigated. The real question is, what do we do about this? How do we shape our laws and society to minimize the damage from this struggle, and maximize the return? The essay you pointed me at, like almost all Western religious works, marches inexorably towards one answer to that question: Defer to the "objective" morality described in some holy artifact, and to those who have been appointed to study it, because if we simply assume that all good things flow from that artifact, then everything else resolves itself. In William Lane Craig's case, that artifact is apparently the Ten Commandments.
This, in practical terms, is not an "objective" morality at all. The only thing about the Ten Commandments that could be called "objective" is that they were written before anyone currently living was born. William's essay caricatures humanity's innate moral sense, for the sake of shoehorning God into the process of moral refinement, and -- isn't that a coincidence -- he has a particular religious artifact in mind.
Unfortunately, even if assumed to be true, an objective morality does NOT constitute support for the veracity of the numerous religious texts and customs that claim to describe it. They remain human-inspired fictive works. But this is beside your point: You require, you demand, that morals derive from a force entirely beyond humans and the process that evolved them. I don't know why. Apparently you lack humility. According to Craig, a soldier's sacrifice for his family is "meaningless" if it is not sanctioned by a law from God. The soldier, and the family, will tell you different.
As I said before:
1. Humans are the primary agents of morality.
2. Therefore, morals are measured by how well they RESPECT humans AS MORAL AGENTS.
The essay you gave me does nothing to refute the suitability of these two succinct points as a guideline for codifying morals into law. In fact, the Ten Commandments themselves are only suitable as moral law as far as they conform to point 2 of this standard. The majority of them, about exclusivity to god and taking a day off, are entirely frivolous.
Again, I suggest that you meditate on the process of moral refinement that has led civilization to disregard the Bible's advice about stoning disrespectful children to death, to gradually reject circumcision and other mutilation rites, to reject the ownership of slaves and all the supposedly "right" methods of keeping them, to reject many of the traditions that reduce women to chattel, et cetera. You will find an increased respect for the process of moral self-determination - an increased respect for humans, ALL humans, even slaves, children, and women, as moral agents - in THIS life, not some afterlife - at the core of these changes. No divine hand is required.
Heck, all you need to do is look at the language itself: The Ten Commandments prohibit murder and adultery, but nowhere in the Bible did anyone feel the need to define murder and adultery. We knew, people knew, what those were and how they were wrong, by the time the Hebrew language ITSELF was constructed. Now why would that be so? Our moral compass was already functioning, compelling people to place those laws on the list, where they almost appear tacked-on. For in God's purview, why would there be a need for anything other than the laws about exclusive, unmediated worship of Him? The road towards "objective morality" does not necessarily have to lead anywhere good, after all. It just has to lead.
For example, in his exaltations of "objective morality" as delivered by God, William Craig proclaims that it is supremely satisfying because, "despite the inequities of this life, in the end the scales of God’s justice will be balanced."
That is not a call to action against injustice. That is a call to let the wicked go unpunished, since they will supposedly be punished in the afterlife. No thanks. We can - and must - balance the scales of justice on our own.