What does the concept of the final cause teach us about the real world Aristotle?

Aristotle pointed out the purpose of everything, in Christian terms, God showed his purpose for mankind, and that he is the only being that knows our true purpose, because he is the efficient cause. It questions the teleological of the universe.

Some parts of the universe appear to have no purpose for example its magnitude and therefore 'purpose' is essentially a feature of consciousness which cannot just be assumed of the inanimate.