Not to a relativist, but for a moral objectivist, morality is a definite sign that a God may exist.
Basically individuals come from one of two camps of thought regarding moral acts. The first camp Moral Relativists, consider all morals to be relative. They assert that morals are merely human constructs that have been developed by man through out time, that they change in regard to the times and the individuals that retain them. On the other hand, the second camp, Moral Objectivists submit that there are actual truth values ie; good/bad associated with moral acts. That charity is in fact "good to do" and that we "ought" to do it...That stealing is "bad to do" and we "ought not" do it. That this truth value is unchangeable and permanent and that circumstances and intent affect only the moral culpability of the individual...they do not make a good moral act bad or vice versa. While both are beliefs and can not be proven with certainty one way or the other, it seems there are actually fewer flaws in the objectivist opinion. Although acceptance of it requires a guiding force outside of man's rationale... a huge stumbling block for some.
Relativists are required to accept that moralities can't improve per say only change..in order to judge two moral codes to see which was better would require a standard outside of both which relativism can not accept. Most people seem to think we have moral progression, relativism can make no sense of this.
In opposition to the objectivist stance proponents of relativism rightfully point out that what we witness in reality is that morals seem to be relative as different societies and individuals have different perceptions of what is or isn't moral. While this is true the objectivist does not claim that an ultimately good moral code has necessarily been revealed to all only that it exists outside of all, in addition objectivists point out that we are free to refuse to acknowledge any objective moral truth.
What does seem apparent is that regardless of the position one accepts to believe, is that all people seem to be drawn to do good and avoid evil regarding moral acts.