Personally, I believe that "right and wrong" are concepts created by humanity(and potentially some other species too) to keep each other from harming each other. Right vs wrong are based off of our feelings, and only apply to humanity, whom hasn't always existed, and will not always exist. Basically, in the grand scheme of things...there is no right and wrong. So certainly, sin is not real.
The bugle sounds as the charge begins
But on this battlefield no one wins
But on this battlefield no one wins
- Iron Maiden, The Trooper