Elizabeth Eliot has said that C. S. Lewis was one of those rare people who seemed to have "thought-through" everything. Here is one of my favourite quotes from C. S. Lewis. It is taken from "Mere Christianity" (one of my favourite books), and explains in a way overflowing with genius, one of the hardest truths in Christianity.
Another difficulty we get if we believe God to be in time is this. Everyone who believes in God at all believes that He knows what you and I are going to do tomorrow. But if He knows I am going to do so-and-so, how can I be free to do otherwise? Well, here once again, the difficulty comes from thinking that God is progressing along the Time-line like us: the only difference being that He can see ahead and we cannot. Well, if that is true, if God foresaw our acts, it would be very hard to understand how we could be free not to do them. But suppose God is outside and above the Time-line. In that case, what we call 'tomorrow' is visible to in Him in just the same way as what we call 'today'. All the days are "Now' for Him. He does not remember you doing things yesterday; He simply sees you doing them, because, though you have lost yesterday, He has not. He does not 'foresee' you doing things tomorrow; He simply sees you doing them: because, though tomorrow is not there yet for you, it is for Him. You never supposed that your actions at this moment were any less free because God knows what you are doing. Well, He knows your tomorrow's actions in just the same way--because He is already in tomorrow and can simply watch you. In a sense, He does not know your action till you have done it: but then the moment at which you have done it is already 'Now' for Him.
"Mere Christianity" pp 145-146
