In what sense is the will 'free', either theologically or scientifically?It is not
Theologically, an omnipotent omniscient god made the universe, necessarily knowing in advance everything that would ever happen (and implicitly approving it), including everything you'll ever think, say or do. Such a god must therefore have moral responsibility for everything, since nothing can happen except according to [his] will, which since [he]'s also perfect won't have changed in the 14 billion years or so since [he] did it.
Scientifically, the brain works by complex interacting chains of cause+effect, likely interrupted at various very small points by events of quantum randomness, though such an interruption effect hasn't been shown.
One way or the other it doesn't look good for free will. How do you explain it? How can any brain make a decision independently of its mechanisms, conditioning and hormones, let alone its predestination?