We do, it's just that God's will is freeer, as He sits outside of time and space, knowing how we will act before we do, even as we really do act.

It's a bit difficult to square, but God created everything and isn't sitting in anticipation of what will happen, nor are you a puppet in which God micromanages your every move.

God knows us, and has already selected His Elect based on our hearts and the actions we will commit of free will, which God already has knowledge, and therefore knew who was His at that time or Creation.