Man can only separate himself from God (i.e. deny he is a created being) by making himself one with nature. Although he rejects the idea of being a creature made by God, he soon finds he doesn't really like thinking of himself as an animal either.
Man can either be a child of God or a child of nature. This is his dilemma. This is the choice he has to make. In our day a lot of people are trying to be both. They claim they are trousered and skirted apes, but they don't want to see themselves as one with nature either. e.g. they want to have laws that apply to humans but not to animals... all the while claiming to be animals. They want to say x is 'unnatural' behavior, all the while claiming to be the offspring of mother nature. They claim to be followers of logic (over 'superstition') but contradict themselves at every other step along their crooked way.
These contradictions speak to man of the fallaciousness of his non-christian world views. (We can see these contradictions as a revelation of God.) Man proclaims his independence from God by declaring his animal origins, but yet he knows better, he knows he's not an animal. We can see evidence of this knowledge in all the laws he creates for himself... or should I say creates for others. He says one thing (in the classroom) and does the opposite when he steps outside the classroom. Wanting to be rational, he ends up being irrational. Darwin offered him a way to escape God, and he went down the rabbit trail... only to find himself in an intellectual and spiritual dead end. He doesn't want to be an animal or a man it would appear. He doesn't want to be a child of God or a child of nature.... but he can't see a way out.
Summary;
Caught in a dilemma he can't find a solution for, modern man tends to cop out by ignoring the problem. "Oh well, why don't we forget the whole thing. Thinking is such a drag. Let's try that new restaurant, and have a bottle of wine. Philosophy! Who needs it."