I believe that it is God is "not willing that any should perish, but that all should come to repentance." But, God doesn't force anyone to accept His free gift of salvation. As the Holy Spirit convicts, God allows man to choose wether or not to respond to that conviction. Those who choose to respond to that conviction and come to repentance become part of the elect, those who reject the Holy Spirit do not. While God may know who will accept and who will reject, it doesn't change that fact that those people had a free-will to make the choice.
Our simple human minds may not understand how God can know who will accept His gift of salvation and who will reject it, all the while allowing them to make the choice, just like our simple human minds don't fully understand eternity, the trinity, etc. Just becuase we can't understand God's mind, doesn't change the facts, we can't use any "doctrine" to try to make the complex things of God easier for our simple human minds.
Our simple human minds may not understand how God can know who will accept His gift of salvation and who will reject it, all the while allowing them to make the choice, just like our simple human minds don't fully understand eternity, the trinity, etc. Just becuase we can't understand God's mind, doesn't change the facts, we can't use any "doctrine" to try to make the complex things of God easier for our simple human minds.