Lewis talks about God’s “Timelessness” — His attribute of being beyond Time. God created Time, so He transcends it; He is not bound by it. So, He has “plenty of time” — or rather, He has no time limitations — to listen to our prayers, for example. He is like an author of a novel — He is not constrained by the “invented time” within the story, unlike the characters He created. We, on the other hand, experience Time as a continuous “stream of moments” — one moment followed by another, and so on.
God did not lose His Timelessness when He entered human history in Jesus. Yes, He lived life as a human being, but He was or is also fully God.
Lewis also talked about human free will and God’s omniscience. Some people object that because God knows what we are going to do in the future (since He is omniscient), we are not really free. Lewis argues that that’s not true. We are still actually free: Again, God is beyond Time. He simply watches over us as we make our decisions. His watch over us and His knowledge of what we’re going to do doesn’t determine our ability to choose our actions. Therefore, we’re free.
I like how Lewis compared God to an author of a novel. Since He “invented” the Time within the story, He is not really bound by it. So He has “all the time in the world,” so to speak, to spend with each of the characters. It’s a wonderful realization because it assures us that God has more than enough time for each and every one of us.
The subject of human free will and the omniscience of God is tough to comprehend. But I agree, as far as I understand it, that there’s no contradiction between the two (free will and omniscience). God’s knowledge of the future does not influence or determine our ability to choose freely our actions. His knowledge of what we’re going to do does not really eliminate our options, nor does it take away our freedom to choose.