Did God Harden Pharaoh's Heart?

What we have in Exodus is this: God says "The Lord said to Moses, “When you return to Egypt, see that you perform before Pharaoh all the wonders I have given you the power to do. But I will harden his heart so that he will not let the people go." - Exodus 4:21

But how is this fair? God hardens Pharaoh's heart, preventing him from repenting and letting God's people go and then God punishes Pharaoh for not letting God's people go? This doesn't make any sense! An atheist posed this question to me one time and I didn't know the answer to it, so I did some research. Fortunately, I found a good answer to it.

This is what my Apologetics Study Bible has to say on the subject.

"The Bible teaches that people are free to make choices (Genesis 2:19 Ezekiel 18:2-32) God is good (Psalm 25:8; 34;8; 100:5) and always acts consistently with His nature. Yet people can choose to rebel against God's goodness and consistent rebellion can lead to their hearts being hardened. As the old saying goes 'The same sun that melts butter also hardens clay.'Egyptian Pharaohs believed they were divine and pharaoh would have never been inclined to surrender to the Israelite's God. Each time God placed a demand on him, he became more determined to resist. Thus, it was both God's demands and Pharaoh's own pride motivated stubbornness that led to his hardened heart. God would use Pharaoh's stubbornness for a good end, to demonstrate his power and extend his reputation."

So God didn't intentionally harden his heart. But God DID harden his heart by continuing to demand him to let the people go. If God didn't keep demanding the pharaoh, his heart wouldn't have been hardened. It's the same way that we say a person angered us. You could say "Tom angered me". Well, Tom didn't take over your mind and cause you to feel the sensation of anger. He merely did something that provoked your angered response. In the same way, God didn't take over Pharaoh's heart and mind and caused him to resist Him. Rather, it was God's insistent demands that caused Pharaoh to freely choose to harden his heart against God. So, God DID harden pharaoh's heart in the same way many people have "angered me".

I think this interpretation is the most reasonable one based on the fact that The Bible talks about the hardening of Pharaoh's heart from 3 different perspectives. In one verse it says that Pharaoh hardened his heart. In another verse it merely says that Pharaoh's heart was hardened but doesn't mention the source of hardening, and in another verse it says that God hardened pharaoh's heart. The explanation above would make sense of The Bible saying that it was BOTH God and Pharaoh who hardened Pharaoh's heart.

Exodus 8:15 (pharaoh hardened his heart)
Exodus 8:32 (pharaoh hardened his heart again)
Exodus 14:8 (God hardened pharaoh's heart)