To what extent do we as humans have free will and to what extent has God predestined our lives?
If God knows predestines / has pre-knowledge of something, that knowledge is done in time. Anything in time has a beginning; i.e., it is finite. God is infinite, God is outside time. God by His nature doesn't predestine or foreknow. He simply knows and destines.
Also, it isn't a dichotomy. Both "we as humans have free will" and "God destines our lives" are perfectly true statements.