My thoughts are that this is nonsense, that a person is the definition of good is what is illogical. I think that to say god himself is the definition of right and wrong and that we cannot know what is right or wrong without god is sociopathic, because this provides that right and wrong are meaningless in general and unless god weighs in on it then it can't be right or wrong.
Humans cry, laugh, weep, feel happiness, sadness, pain and anger with or without god. Moral systems are a part of who we are, they are a basic part of humanity and gods did not give that to us. Religions got their morality from humans, not the other way around.
The question that without god we cannot have morality is not providing that gods grant morality, but rather that the moral system that values god is the right moral system to have.