"Adam was a mythical figure who never really lived."
Adam is a key figure in Scripture. He is described as the "first Adam," the one who brought sin into the world. He made it necessary for Jesus, the "last Adam," to atone for all humans, and then rise from the grave with the promise of complete redemption for fallen man and fallen creation. If Adam was just a myth, we would not be able to fully understand the work of Jesus. If Adam and Eve were not real, then we ought to doubt whether their children were real too, and their children...and then we ought to doubt the first 11 chapters of Genesis, and so on. All the genealogies accept Adam as being a literal person, so their children Cain and Abel (Genesis 4:9,10; Luke 11:50,51) must be real too. Jesus was descended from Adam, and it is impossible to be descended from a myth.