Predestination or free will?

I've always struggled to see why, if they have a basic understanding of God's nature, people should see a contradiction between them.

Romans 8, 28-30
And we know that in all things God works for the good of those who love him, who have been called according to his purpose. For those God foreknew he also predestined to be conformed to the likeness of his Son, that he might be the firstborn among many brothers. And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified.

So first God already knew what we were going to do - He foreknew those who would respond of their own free will. Therefore He determined that they would be changed to be like His son (in the context of the passage we're talking about salvation both as lifestyle and after our earthly bodies are dead). And in order that they might become like that, He called them, knowing that they would respond to that call, justifying them through the blood of Jesus and, ultimately, changing them from being unspeakable into those who are.... I didn't want to use the word glorious because it is of little meaning and value these days ....prepared and suitable to stand full time in front of the God who created the universe and holds all things together by His will.