I can't yet decide whether those unpredictable atoms weren't determined to be unpredictable by the codes inside the material of the big bang.

I can't see my behavior being much different whether or not I have free will. But guilt takes on a diferent shade without it. Our view of the sinner and of the criminal would soften, I believe, were we to treat their behavior as if it had been determined.

Quarantime rather then incarceration. Indeterminate eternal purgatory-like-place rather than heaven or hell.

Consider free will a cultural meme mutating in reaction to an environment of religious zeal that needed a 'fall guy' without which heaven and hell would lose significance as well as any need for a concept of sin to craft a key to enter either one.