A while back on the Classical Deism server, the topic of the Euthyphro dilemma came up. The Euthyphro dilemma can be summed up as asking, "Is the good actually good because God wills it, or does God will it because it is good?". It's certainly an interesting question, no doubt. However, it was interesting that the Deists on the server tended towards the latter while the Theists tended towards the former. Though I did not realize it instantly, there's a very good reason behind both of those tendencies.
Though there are many proposed answers to the dilemma, most fall into either of the two choices described above or dismiss it as a false dilemma. The case for morality being dependent on God or because God wills it rests upon the idea that goodness would lose its value if not based in God. In many Theist traditions, it seems fairly straightforward that if goodness is based on something necessary and immutable, then it is merely a suggestion rather than a true principle. There does seem to be some truth to that, but there are cases that can be pointed to where it seems intuitively wrong. Most famous religions have at least 1 example of their God commanding or willing an act that we would consider normally immoral. Yet, since it is willed by God, it becomes moral. Or at the very least, moral in that circumstance.
The major problem with such an approach is that it seems to lead to self-refutation. How does one assert that God is a perfectly moral being if the concept of morality is dependent on God? Even if we suppose that it could be true for a moment, there'd simply be no way to prove that God is perfectly moral. It would have to be taken as an axiomatic belief that there exists a perfect being out there that is the source of morals, without which the concept would cease to exist. A sort of budget presuppositionalism. Though, while appealing within a Fideist framework, it doesn't stand up to philosophical scrutiny.
I do find the latter option to also be insufficient on its own. If God wills a moral system because it is good independent of its existence, then any attempted proof for the existence of God based on its necessity is in trouble. After all, if there exists a necessary concept independent of a necessary being, then there is a contradiction. The only way this remains coherent is if they are identical rather than separate. While that has conventionally presented problems with omnipotence, both seem to survive if we bind them to logic as a transcendental. Omnipotence becomes the ability to do what is logically possible, and thus God not being able to act immorally is not an issue, as it is not possible within its nature.
I am committed to the notion of a universal ruleset of ethics, though delving into it would make the article too long. I will address moral skeptics at a later time, but for anyone who agrees in a sort of objective morality, they must have the preconditions for the possibility of proving it. The usual Theist answer of God makes right would make us unable to ascertain what "right" is because it would be a fleeting, dependent concept rather than axiomatic.
What I observed challenges the notion that Theists are the side committed to morality. If anything, they have had a large role in reshaping it away from what it ought to be. Morality does not shift on the whims of God. That is what would truly make it meaningless. The justifications for several Theist acts upon the basis of "God wills it" are mistaken and should be looked at accordingly. We ought not to concede the morality framework to Theists for no other reason than it not being true. If we do not, we risk rendering it meaningless.