text: ..."Original Sin and the Fall from grace is the only possible explanation for God's becoming man in order to redeem the human race."....
  
  The 'Word could have become flesh and lived among us' simply out of Love. God so loved the world that He came to live among us. We all do, indeed, have plenty of personal sins to be redeemed' of. But inheriting someone else's sin is not the ''only ' possible explanation for why  Jesus came.
  
  As Scripture scholars tell us : if there was not actual Adam and Eve there could not have been any actual historical 'sin' or 'fall' to be inherited. It was inspired by God to be a myth form of writing. So there must be a better explanation.
  .. "could an absolute, perfect God have deliberately created such an imperfect world?"....
  That is what the author(s) of Genesis tried to explain in their myth story. The real answer is : Yes. This is the world God gave us.  God created what He did. Maybe even, He created evolution. We better learn to live  with it & in it.