I do believe that God is outside of time, that he is all-knowing, all-powerful, omni-present, etc. He knows the end from the beginning and it still fits within his plan that his offer of salvation applies to all mankind from the past, present and future. Jesus' own words say God so loved the world he gave his only son that whosoever believes in him would not perish but have eternal life.
Where the problem lies, I think, is when we humans try to figure out every thing about God and his ways. There are just some things that cannot be grasped with a finite mind. Jesus even said he told people of earthly things and they didn't believe, so how would they believe if he told them of heavenly things? It is interesting to discuss theology like this but there has to be a point where we say "I don't understand everything I know about that." and leave it there. :o)
The verse in Isaiah says God "declared" the end from the beginning. So God doesn't just "know" what happens in life; He "declares" it all. He ordains all life according to His perfect purpose.
Jesus' own words say God so loved the world he gave his only son that whosoever believes in him would not perish but have eternal life.
Yes, aren't we fortunate God loves what He has created? And yet Christ says He doesn't pray for all the world but only for those whom God has given Him to redeem.
I agree there is a lot about God and life that will always remain a mystery to us in this life. But I don't think the comforting truth of predestination falls into category. I think God has revealed His control of His creation pretty explicitly. Thankfully.
"Who hath saved us, and called us with an holy calling, not according to our works, but according to his own purpose and grace, which was given us in Christ Jesus before the world began" -- 2 Timothy 1:9"For the children being not yet born, neither having done any good or evil, that the purpose of God according to election might stand, not of works, but of him that calleth" -- Romans 9:11
If you have a couple minutes here's an excellent understanding of predestination by Greg Bahnsen.