For something to be objective, it must pursue some goal as its object. The goal must be definable in terms which do not admit opinion.
IF the existence of "God", (and for Christians, it's their god), makes for objective morality, then the object is to do as "God" commands.
Although one might manufacture a reason for oneself, there is no need to have any inkling of why a particular act is morally right, except to believe that "God" says it is. If, for the sake of argument, "God" commands someone to kill another person or group of people, then it is moral to do so, and there is no need to understand what makes it moral, other than that "God" said it is.
If we take an atheist position, can we come up with a moral code, which is objective, and not a matter of opinion? I suspect that the answer is: 'Yes we can', and Matt Dillahunty, and Sam Harris have attempted to do so. Their principle of morality is to look at consequences. The task of setting up a moral code, independent of any divine commandment is not easy, because opinion can easily taint an individual's analysis of the case-in-point. But the same can apply to a god-based moral code. Even if one accepts that there is a divinely ordained moral code, it is not always clear-cut as to what is moral. The basic tenet is: It's OK if "God" says it is. But how can one know what "God" says on a particular issue? The religious may say that they use prayer, and get guidance from "God". I can't see that as any different than an atheistic person who simply uses their mind, and comes up with moral answers in their own right.
So can we construct a moral code that is objective? I say that we can be as objective as the religious can, and a damn site more responsible for our actions as good-thinking atheists, than simple god-following theists.
If you want to say that {"anything goes", by default is an objective moral system and standard in [and] of itself }, then there seems to be no goal-seeking, and no code. I'm not happy with that, as an example of 'objectivity'.