To understand free will I think that you have to ask yourself some fundamental questions about God, as follows.
Question 1: Do I believe that god is omnipotent and omniscient?
All that comes down to is how powerful do you believe god to be. Omnipresent applies also, but it's not so relevant to this discussion. The most relevant here is omniscient.
If you believe God to be all of the above, then...
Question 2: If God is omniscient, and knows everything-and I mean everything-then how is it possible that he wouldn't know what I, or anyone or anything in this universe that he has created, will do?
Now this question does not only apply to what they will do next. If God is truly omniscient, he would have known what every living thing that he created would do throughout the life span of the universe, before he had even created it. Because only that would be true omniscience. if you follow that, then...
Question 3: If God knows what I will do throughout my whole life, and knew this before he had even created the universe, how can that count as having free will?
And it can't. You decide what you will do each morning when you wake up, but God already knows if you're going to have coffee or orange juice on the first Friday morning of next month.
From our perspective it truly does feel like we decide, and we do. God is not sitting there with a video game controller telling you when to go to the bathroom. Why would he have to be if he were truly omnipotent? If he decides to get up and make a sandwich you will not forget to go to the bathroom until you loose all bowel control. (forgive the analogies)
But he knew before time in this universe began that you would pick the blue tie over the red for that big meeting on Wednesday.
I think that God isn't given as much credit as he deserves. People try to humanize him. Try to make it look like he makes mistakes just like the rest of us. But why would he. People throw around the word omnipotent without taking the time to fully grasp what it means. True omnipotence means ALL powerful. Think about it.
We don't have free will. Just the illusion of free will, which, when you're down here, is about the same thing.
The point is that from down here, it really doesn't matter that we don't have free will, because it feels like we do. From gods perspective though, every tiny detail was planned out beforehand, and an important piece of the whole puzzle.
Everything that happens is supposed to happen. It has to be that way. Because a truly omnipotent God wouldn't make mistakes.