Free will means all people have partial salvation. And all they must do is provide what’s needed to complete it. So different groups fill in the blanks with different levels of obedience to complete the task. They are half saved having free will. And fully saved by choosing to obey.
But it always results in people trusting in themselves for salvation. God only opening heaven’s doors to those who complete the task.
But this destroys faith in Christ as savior. Free will is a walk by sight trust in yourself for salvation based on rules you fulfill. So trust is always in self who fulfills them.
But without free will, people have to look for a power beyond themselves to save. Only when they come to the end of themselves with nothing more they can do, will Christ become their only focus of faith.
As Martin Luther said; "First, God has promised certainly His grace to the humbled: that is, to the self-deploring and despairing. But a man cannot be thoroughly humbled, until he comes to know that his salvation is utterly beyond his own powers, counsel, endeavours, will, and works, and absolutely depending on the will, counsel, pleasure, and work of another, that is, of God only.”
He continues; “For if, as long as he has any persuasion that he can do even the least thing himself towards his own salvation, he retain a confidence in himself and does not utterly despair in himself, so long he is not humbled before God; but he proposes to himself some place, some time, or some work, whereby he may at length attain unto salvation. But he who hesitates not to depend wholly upon the good-will of God, he totally despairs in himself, chooses nothing for himself, but waits for God to work in him; and such an one, is the nearest unto grace, that he might be saved." Martin Luther. The Bondage of the Will.
So in the end people have sight faith, trusting in tangible items keen to the senses. But only few have faith sight where they trust in Christ alone to save them.