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.