Could the characters “Cain and Abel” and “Jacob and Esau?” be perhaps
symbolic or representative of a species, not actual individuals? Or be
real individuals that have symbolic meaning for different species that
have existed in the past?

Personally, I would hold out that Cain and Abel (and Adam and Eve for that
matter) were real people who actually lived. That is certainly the implied
tone of the text of Genesis and the New Testament writers seem to imply
that they accepted them to be real people (ex. Romans 5 1f). Having said
that I would concede that one could take them to be symbolic
representatives of the first humans without doing irreparable damage to
the text. My opinion is that they were real people who actually lived, but
I would not reject as a non-Christian someone who felt they are
representative of the first humans.

As for Jacob and Esau (and therefore Abraham and Sarah), I am convinced
that they were real people who did the things described in the Old
Testament. I believe this for both biblical and archaeological reasons. I
do not see any conceivable way to argue that the Bible is inspired by God
in its totality if Abraham did not live. The entire argument in Romans
chapter two would fall apart if Abraham is a fiction. The entire concept
of the Jews as a nation is based on Abraham and his descendents. Besides,
if you read my book, Reasons for Belief: A Handbook of Christian Evidence
(www.ipibooks.com) you will find a chapter describing a significant amount
of archaeological evidence which makes belief that Abraham was a real
person very believable. Also, see an article on the subject at this
web-site, History, Archaeology and the Bible. I definitely believe that
Jacob and Esau were real people.

John Oakes, Ph.D.