It has already been said that without Genesis the Watchtower version of The Truth falls apart. That is, if the Adam and Eve story isn't true, PSacramento, then how could the story of God sending his Son down to redeem us for that Original Sin be true? The New Testament gospels of Matthew and Luke present the geneology of Jesus of Nazareth tracing back to Adam. Is this allegory? If so, what is the purpose?
The story of Adma and Eve is the story of Man's Fall from God's grace, in a nutshell it is about Man ( symbolised by Man and Woman) deciding that they do NOT need God and that they can do it themselves, and their Fall because of that.
Jesus is God's reconcilation: Nothing that Man can do will ever get Man "back up there" ( In God's grace) so God "comes down" to Us in the form of his only begotten Son incarnate in a human body ( The union of God and Man as it was and supposed to be) and by Jesus's life and death, we are reconciled with God's grace - Man could never get back up there so God came down to Man and gave the gift of Grace and resurrection (eternal life).
Why did Jesus have to die? Because he ( the human form) could never have been ressurected if he hadn't and could never have shown us OUR futre:
Resurrected, in union with God, the spirit living in us all.