Lately I've been thinking a lot about what God knows and how that relates to human freedom. Sixteenth century Jesuit theologian Luis de Molina has been helping out quite a bit. Specifically I've been thinking about the question: Does God know things before they happen?
There are at least four ways Christians seem to answer this question.
No: God is just along for the ride, similar to us
You could just say that God doesn't know things before they happen. This is a popular option for a lot of people nowadays, especially in the mainline and Methodist circles I run in. Often people who advocate this position are rightly worried about God getting blamed for evil things that happen in the world. People do horrible things sometimes, and God is just as appalled as we are. God is not the author of evil; instead he is there with us as we suffer. This position is intended to be compassionate and pastoral, but its disadvantages are significant. This God might be really smart, but he is far from the all-knowing God of classical Christian teaching. Furthermore, biblical prophesy becomes a problem. For instance, how does Jesus know that Peter is going to deny him three times (Mark 14:30 and parallels)?
Yes, because God wills everything that happens
One way God could know everything before it happens is if God somehow is the cause of everything that happens through his will or decree. This is what a lot of Calvinists believe. It's basically the opposite of the first answer, and is great in its view of God's power and knowledge. There's no problem with classical theism or biblical prophesy here, but there is a problem with human freedom and with evil. This view seems to make God complicit in all of the bad things that go on in the world, and it makes God's judgment of sinners seem capricious and arbitrary: if God made Judas betray Jesus, it doesn't seem fair for Judas to be punished for it. More trivially, this view doesn’t seem to match our experience - I genuinely feel like I chose to have egg salad for lunch last Friday, for instance. So God's power and knowledge are elevated here, but only at the cost of God's goodness and justice - and at the cost of human freedom.
Yes, because God exists outside of time and so sees all of history at once
God could know things before they happen if God's eternity places him somehow outside of history, and therefore able to view it all at once, like a student viewing a timeline in a history textbook. This and the next view are closest to the views of many church fathers, as well as that of the founder of Methodism, John Wesley (apologies to my answer #1 Methodist friends). On this view, God exists outside of time, and so every moment that has ever or will ever occur is present to God all at once. And so God is all-powerful and all-knowing because he's able to see the whole, but people are still free to do what they want in the course of history. God doesn't get blamed for evil because he is allowing human freedom to run its course, but God is still able to act in history and can thus inspire things like prophecy and do things like perform miracles. This view is kind of abstract and conceptually difficult, but if we could understand it perfectly it probably wouldn't be divine, right?
Another possible issue for this view is the fact that God seems to know hypotheticals too. Jesus said, “Woe to you, Chorazin! Woe to you, Bethsaida! For if the miracles that were performed in you had been performed in Tyre and Sidon, they would have repented long ago in sackcloth and ashes” (Matt 11:21 NIV11-GK). Of course those miracles weren't performed in Tyre and Sidon, so how could God possibly know that they would have repented? If you're thinking it's because God is really, really smart, I think you're right. But that means we need to add something else to this third view: God doesn't just know future events simply because he exists outside of time and he can see them. So, here's a fourth view, complimentary to the third.
Yes, because of "middle knowledge"
According to Luis de Molina, God knows the future through three types of knowledge. First, God perfectly knows nature and how it works. The planets move in this way, your internal organs work like this, and if you hit a ping pong ball in exactly that way, then it will go along this path. Second, God knows what he is going to do in the universe; God knows exactly the extent to which he will act in the universe in history. And third, God perfectly knows how free agents will behave in every possible situation they might be put in. Molina calls this third type of knowledge, "middle knowledge." God knows that Tyre and Sidon would have repented if they had seen those miracles of Jesus, even though that situation never happened. And God knows that Peter is going to deny Jesus three times.
Here's the key though: Peter is free not to deny Jesus. When Peter denies Jesus, it is really, genuinely Peter doing that. Peter was able to not deny Jesus, but if Peter wasn't going to deny Jesus, God would have known that too. In the same way, God knew Judas would betray Jesus, but Judas didn't have to betray Jesus. But if Judas wasn't going to betray Jesus, God would have known that too.
So God is all powerful and all knowing, God is able to be perfectly good and just, and on top of all that, God is able to know hypotheticals too. Not bad, huh?