For example child abuse, rape or genocide – would never be acceptable to anyone on the planet if perpetrated against them or someone they love! Even if a whole society agreed on an immoral or evil thing – They could never justify it as right or good but as collateral or a necessary evil under the circumstances.
If there was no such thing as absolute morality then there would be no 'right' or 'wrong,' just things that you or your society happen not to like. Murder and Rape would not be wrong; they would just become manmade objections. The question then becomes: 'If man is the measure of all things which man? -Which society? If someone with enough power happened to like rape and murder, what right would we have to impose our morality on him? What would be wrong with the person or society, with the power, imposing their morality on you?
If objective moral values cannot exist without God, and objective moral values do exist, then it follows logically that God exists. Moral objectivity doesn’t exist outside of humans – it is inherent and therefore programmed within us (biologists call innate). Where there is programming there is a programmer. This innate ability is of an advanced consciousness and has a purpose.