Summary: Many physicists and scientists now argue that humans do not have free will. The Bible teaches we are free to choose.
Do we have free will?
I think most people are actually not really interested in this question.
But there are some really interesting and important aspects to this question.
John Searle argues philosophers have not really made any progress on this question in the past hundred years or so. I think he may be right about that.
The ultimate objective test of free will would seem to be: Can one predict the behavior of the organism? If one can, then it clearly doesn't have free will but is predetermined. On the other hand, if one cannot predict the behavior, one could take that as an operational definition that the organism has free will ... The real reason why we cannot predict human behavior is that it is just too difficult. We already know the basic physical laws that govern the activity of the brain, and they are comparatively simple. But it is just too hard to solve the equations when there are more than a few particles involved ... So although we know the fundamental equations that govern the brain, we are quite unable to use them to predict human behavior. This situation arises in science whenever we deal with the macroscopic system, because the number of particles is always too large for there to be any chance of solving the fundamental equations. What we do instead is use effective theories. These are approximations in which the very large number of particles are replaced by a few quantities. An example is fluid mechanics ... I want to suggest that the concept of free will and moral responsibility for our actions are really an effective theory in the sense of fluid mechanics. It may be that everything we do is determined by some grand unified theory. If that theory has determined that we shall die by hanging, then we shall not drown. But you would have to be awfully sure that you were destined for the gallows to put to sea in a small boat during a storm. I have noticed that even people who claim everything is predetermined and that we can do nothing to change it, look before they cross the road. ... One cannot base one's conduct on the idea that everything is determined, because one does not know what has been determined. Instead, one has to adopt the effective theory that one has free will and that one is responsible for one's actions. This theory is not very good at predicting human behavior, but we adopt it because there is no chance of solving the equations arising from the fundamental laws. There is also a Darwinian reason that we believe in free will: A society in which the individual feels responsible for his or her actions is more likely to work together and survive to spread its values. -Stephen Hawking, Black Holes & Baby Universes . . . pp. 133–135
So Stephen Hawking is suggesting we do not have free will, but we’ll work together better if we act like we do. Yet later Stephen Hawking says “We are each free to believe what we want” (Curiosity). If our actions and thoughts are determined by mechanistic processes, we are not even free to think or believe what we want-we are programmed to believe what we only appear to choose.
Roger Penrose, who shared the Nobel Prize with Stephen Hawking, dove into the subject as well:
My own point of view, although it is not very well formulated in this respect, would be that some new procedure [CQG-Classical Quantum Gravity] takes over at the quantum—classical borderline which interpolates between U and R (each of which are now regarded as approximations), and that this new procedure would contain an essentially non-algorithmic element. This would imply that the future would not be computable from the present, even though it might be determined by it. I have tried to be clear in distinguishing the issue of computability from that of determinism, in my discussions in Chapter 5. It seems to me to be quite plausible that CQG might be a deterministic but non-computable theory. -Roger Penrose, The Emperor’s New Mind
In English: Penrose argues that our mental process and free will may not be mathematically describable.
Michio Kaku (a physicist who is working on a unified theory of quantum mechanics, and built a 40 gigawatt particle accelerator in his garage when he was a teenager for a highschool science project) argues that because of the Heisenberg Uncertainty Principle we cannot determine what someone would do based on what has happened before and that, therefore, the question of free will is answered, we have free will, because what we do cannot be absolutely determined by what has happened before. (Big Think video series)
So, the physicists have weighed in and they seem to be divided on the issue. I think there are fundamental deficits with the presupposition that predictability and freewill are absolutely related. Boethius, I believe, answered this issue quite well over 1,000 years ago, as Lady Philosophy explained that simply because you know someone will behave in a particular way does not mean that either 1. You have determined their actions or 2. Their actions are determined simply because they are predictable. Our decision-making processes are, I think, beyond mathematical prediction, or, as Penrose stated, they are non-algorithmic. But even if they could be described mathematically, this in no way implies they are somehow, thereby, pre-determined. It seems to me there is something about consciousness itself which supersedes the physical processes from which it arises.