The argument for God based on our recognition of what is wrong and what is right, commonly named the moral argument, is one strongly supported by the existence of an objective moral standard.
By acknowledging that murdering someone is far more evil than inviting them to your home for a meal, we acknowledge an objective standard, not a subjective one. By claiming that morality is either subjective or relative to a person’s feelings, one places the individual as the highest moral authority—nobody's idea of morality is more or less right than someone else’s, by definition. Not only does this mean that everyone’s view is equal in merit, which seems to juxtapose the abolition of objective standards, but it also morally equates someone like Stalin to Mother Teresa; this seems gravely wrong.
The assurance that a higher power ordained this moral standard, as opposed to a human authority or civilization, is in the universality of moral values around the world. Regardless of culture, we see a consistent acknowledgement that certain practises are frowned upon, such as rape and theft. If morals are purely derived from our desire to thrive and survive, as some atheists claim they are, then why is it not common practise for us to use such actions to get what we want? After all, what I want and believe is just as right as what the next person believes.
The answer lies in the fact that there is an objective moral standard that we all have an innate knowledge of and that works to convict us of our wrongdoings. Reflections of this convicting standard can be seen throughout history, with groups such as the Nazis using the process of dehumanisation to invoke action and limit empathy against the groups they wished to kill. That would not have been required if morality is purely defined by the state or by what a certain individual wishes to do.
None of this is to say that atheists or anyone of another faith cannot know what is good; instead, it shows that we cannot define what is good or bad if there is no standard beyond us. Humanity’s intrinsic value cannot be amassed by the amalgamation of molecules over time, as the Darwinists would like to believe; it must be bestowed by something higher.