"The Test of Free Will: Choosing Between Good and Evil"
For example, Exodus 9:12 says, "And the LORD hardened Pharaoh's heart, and he did not listen to them, just as the LORD had spoken to Moses." If it is literally interpreted and misunderstood, it seems to say that God purposely hardened the heart of Pharaoh so that he didn't listen to Moses. And thus, it seems that he was destroyed by the ten plagues.
However, this verse doesn't mean that God purposely hardened the heart of Pharaoh. It rather means that God allowed Pharaoh's evil attributes to be revealed in his freewill. Even though Pharaoh saw the great signs and wonders that God showed, he didn't believe the word of God's prophet. As it was repeated, he made his heart more and more hardened. It was rather the case that God who showed the ten plagues to him so that he could turn his heart back. But Pharaoh couldn't stand for the good side because of his evil.
Since his heart was evil, even after he chose goodness, he eventually chose evil over goodness later. Likewise, those with evil hearts cannot choose goodness even if they want to. "I will speak good words from now on, and I will act in goodness." People make up their minds, but soon the evil inside comes out again. That's why you are told to circumcise your heart. Only after you circumcise your heart and cast off evil from your heart, can good words and deeds come out. No matter how long you have managed a Christian life, no matter how great the signs and wonders are that you have seen, unless you circumcise your heart, it's useless.
The evil still hidden in your heart will come out, and you will disobey the word of God. "Isn't it better God controls our heart so that we can choose the good side?" You may think like this, but it's against the law of justice. If it were so, there would be no one who cannot become good and receive salvation. There would be no need for human cultivation, and God wouldn't have needed to allow for the evil spirits. All He had to do was create human beings as true children of God in the first place. But, it is against justice.
Without cultivation, true children cannot be harvested. Only through the procedures of experiencing the relativity of things, could people become God's children who know the truth. That's why God is cultivating human beings on earth within His Justice. God gives freewill to each one and entrusts them; He doesn't force His will. And He gives grace and strength and the help of the Holy Spirit to those who choose goodness and follow the will of God in their freewill. On the other hand, the enemy devil and Satan incite those who choose evil and disobey the word of God in their freewill, and lead them to the darkness.
Source from Pastor Emeritus Dr Jaerock Lee sermon