I once heard it argued that God must be very sad, if indeed God exists. The argument basically went: if God truly was omniscient, and knew the past and the future in advance, then it followed that God also knew every other past and future, where each person on the earth made different decisions. God, with His omniscience, has seen things I have done in the past that didn't turn out as well as they did, and has had to face the failures of mine that I, by not making those choices, did not have to face. Conversely, choices I made that led to failure were observed by God, who would feel the disappointment that I didn't make a better choice that God (and only God) knew would lead to a better outcome.
If this is true, God must be very unhappy. For this is really a lose-lose scenario, God either knew what you should have done and is disappointed you did it, or you did what you should and God is pleased with that, but saddened by the knowledge of what would have happened had you chosen a poorer path.
Let's take an example. Let's say on my way to work tomorrow morning there is a sudden, massive car accident right in front of me. I swerve and avoid it, but the car behind me is not so lucky and smashes into the accident. The driver is critically injured. God, being omniscient, cannot be happy that I am well because he feels the suffering of the driver behind me that was not so fast with his steering. Similarly, God gets a double dose by omnisciently knowing how much pain I would have suffered if I had not swerved and avoided the accident.
Or take a real event. God knows what will happen to Americans because of the stimulus packaged being passed as I type this. Perhaps things will turn out great. But if it turns out to be a disaster, God already knows it, and is dealing with that. Further, God also knows what would have become of us if we hadn't passed the stimulus. It might have been much better than if we did pass it, in which case, God has to deal with that. But it might have been much worse than if we had passed it, and God must deal with that also.