Rav Avigdor Miller on Free Will and Hashem’s Will
If Hashem fashions the hearts of a man how is there free will?
And the answer is that it doesn’t interfere with their free will. When it says that He fashions their hearts, it means He gives them certain incentives as reward or punishment. Now, when a man tries to do what’s right he gains incentives – Hashem rewards him with more opportunities. שכר מצוה מצוה — The reward for a good bechira, for choosing good, is another opportunity for bechira. He’ll be given new opportunities to do mitzvos. And if a man chooses to do something wrong, Hakodosh Boruch Hu gives him opportunities to do other wrong things.
But either way, he is the one who starts the ball rolling and he can always stop. If he wishes to make an effort, he can stop that process. So the principle still stands that Hakodosh Boruch Hu does not interfere in man’s free will.