it's not a question of what's "right" and "wrong", even. i'd have trouble defining these things, but that's not why sin needs to be ejected from humanity, as a concept.
the problem with sin is that it creates guilt, and guilt is self-defeating and toxic and destructive. the reason that we need to get rid of sin is actually because we need to get rid of guilt; nobody should find themselves in these situations where they are trapped by their own self-righteousness, and unable to act logically due to a fear of upsetting some kind of unproven force. it just turns us into wrecks, and it needs to stop.
i never, ever want to experience somebody that is lost in guilt and uncertainty over an obvious triviality ever again. we have to conquer this, and leave it behind.
but, that doesn't mean that we can be utility monsters, either, as that will also destroy us. the idea is to place logic in the transcendent position; the same faculties of reason that can help us discard sin as childish can help us understand when we need to behave socially for the benefit both of our selves and of those around us.
and, that is kind of the actual point: learning to truly think for ourselves.