To what extent do we as humans have free will and to what extent has God predestined our lives?
As I see it, God has not predestined our lives but rather He has chosen the believers for Himself and has predestined them to be conformed to the image of His Son Jesus.
Ephesians 1:4-5 (NASB)
4 just as He chose us in Him before the foundation of the world, that we would be holy and blameless before Him. In love
5 He predestined us to adoption as sons through Jesus Christ to Himself, according to the kind intention of His will,
I do not believe that 'free will' is a reality. Our wills are not free. All men in Adam are in bondage to sin. Of ourselves we would not seek God.
Romans 3:9-11 (NASB)
9 What then? Are we better than they? Not at all; for we have already charged that both Jews and Greeks are all under sin;
10 as it is written, "THERE IS NONE RIGHTEOUS, NOT EVEN ONE;
11 THERE IS NONE WHO UNDERSTANDS, THERE IS NONE WHO SEEKS FOR GOD;
Where in the Bible does it say that we have 'free will'? Or that our wills are greater or more important than God's will?
When I chose Christ my Lord it was because He had already chosen me. I did exercise my will but it was because I was already drawn by the Father to do so.
We do make choices but these choices are totally inline with our nature and our natures as sinners are corrupted with selfishness (sinfulness).
This life is not about man's free will. Rather it is about God's glory. We need to ask ourselves if our world view is man-centered or God-centered. It does make a difference.
in the Father's will,
"But may it never be that I would boast, except in the cross of our Lord Jesus Christ, through which the world has been crucified to me, and I to the world."