Does God opening our understanding take away our free will?
No. God opening a person's understanding to spiritual truth does not take away free will or bind anyone to a decision by God to go to heaven or hell. Before spiritual truths can be comprehended, God must open understanding, but that divine act does not override or coerce the human will.
Les teaches that people cannot comprehend spiritual truths unless God opens their understanding. Jesus illustrated this with Peter, telling him that flesh and blood had not revealed the truth to him, but the Father in heaven had. Yet Les insists this divine opening does not take away free will or make a person bound to a decision by God to go to hell or heaven. God must open understanding for spiritual truth to be grasped, but that does not override the will.