Evolution, the scientific theory that best explains the common lineage of living things on this planet, is just one way to prove that the creation account of Genesis is a myth.
Archeology is another way to prove that the creation account of Genesis is a myth.
The textual examination of the Bible using the Documentary Hypothesis, aided by modern archeology, shows that multiple authors with differing agendas had a hand in the writing of Genesis, thereby discounting the belief that it was a product of divine inspiration.
Granted that there may be some history found within its pages but only after the account of the Tower of Babel. Grave internal inconsistencies exist, and it must be noted that modern standards of historical accuracy were unknown to Biblical writers. They were story tellers.
All that brings me to my point: If one doesn't have to believe in sin and redemption, why would one want to? Science, while not a religion, is a liberation from darkness and superstition. Further, the belief that we somehow need these myths to "keep people in line" doesn't speak well for anyone who thinks that way in my opinion. I've known atheists, agnostics, and members of non-Christian religions who were good people, as good and as loving as any good and loving Christian. This is how normal humans act, regardless of culture.
Dave