As a follow-up of God’s foreknowledge/infallibility and our free will, what should I make of this?:
"One of the most common ways [to get] around the difficulty states that merely knowing what someone is going to do does not prevent them from doing it freely. For example, I may know that if you find a $100 bill on the sidewalk you will pick it up, but it doesn’t follow from that that you don’t do so freely. You could refrain from picking up the money; it’s just that I know you wouldn’t want to do so. Likewise, some claim, God’s knowledge of what you are going to do tomorrow doesn’t mean your decisions aren’t free.
It may help to make this point clearer if we compare it with knowledge of what has already occurred. Let’s say that yesterday you had pizza for dinner, and that God (of course) knows that. This doesn’t mean that you didn’t do so freely: you could have had something else. There were other possibilities as to what you might have had. However, the choice you actually made was to have pizza. Now contrast that with God’s knowledge of what you are going to have for dinner tomorrow. Again, there are different possibilities as to what you might have. However, there is only one that you will actually choose, and God knows, in spite of there being other possibilities, which one it will in fact be.
This argument may appear perfectly sensible. After all, in many cases we can predict with pretty good accuracy what someone will do (especially if we know the person well) – and yet we don’t think that someone isn’t acting freely for that reason. So why should it be any different with God’s knowledge?
But in fact it is different, and to understand why we merely need to remember one thing about God: namely, that he is supposedly infallible. That is, God cannot possibly make mistakes; by definition, he cannot be wrong. And that changes things.
As we have already seen, in order for you to be free in the sense being discussed here, it must be the case that you are free to choose from among different alternatives. Your choice of pizza yesterday was free only if it is true that you could have chosen something else instead. And this means that if tomorrow’s decisions are to be free, there have to be different possibilities as to what you will do. Maybe it is the case that you will, as it turns out, have spaghetti for dinner, but nevertheless other alternatives must exist. You aren’t free if having spaghetti is the only thing that it is even possible for you.
But now here’s the problem: if God cannot be wrong, then it is impossible for there to be alternatives to what he knows you are going to have. In other words, it’s not merely that God knows that you are in fact going to have spaghetti, while other possibilities remain. Rather, since it is impossible for God to be wrong, it is also impossible for you to have anything else. Because for there to be another possibility is for there to be the possibility of God making a mistake." (bold mine)