Christians will say the reason there's so much evil in the world is because of free will. Even Christians will 'sin' on occasion, but they believe they can be forgiven. Free will is seen as a bad thing...?
But upon entering heaven (which I'm saying exists for the purpose of this discussion) do we still have free will? If we're not robots in heaven, then what will allow us to be 'us' and do the things we want if not free will? I suppose this can be applied to a paradise too, if anyone still believes in that.