During our study of Exodus 4:18-31, we encountered this difficult statement from God that He spoke to Moses: “When you go back to Egypt, see that you do before Pharaoh all the miracles that I have put in your power. But I will harden his heart, so that he will not let the people go” (v. 21).
At the time, I gave a brief answer to the supposed debate between divine sovereignty and human responsibility by noting that they are both clearly presented in Scripture and that we must simply live with the mystery of how exactly they relate to one another. Even so, as we are studying through the plagues of Egypt, we have been struck over and over again by the hardness of Pharaoh’s heart. Thus, it is worth exploring in greater depth why God chose to harden Pharaoh’s heart at all.
While Exodus does not explicitly give a reason, it certainly comes pretty close to doing so. Consider God’s words to Pharaoh in Exodus 9:16, while warning of the plague of hail: “But for this purpose I have raised you up, to show you my power, so that my name may be proclaimed in all the earth.” God could have erased all of Egypt in the blink of an eye. He could have rained fire and sulfur upon them until the whole country was nothing but ash and dust, just as He did to Sodom and Gomorrah. However, God had other plans. Repeatedly, God has said that both Israel and Egypt will come to know that He is the LORD, that He is Yahweh. So, God raised up Pharaoh for the purpose of displaying the power and greatness of His name through the defiant king.
Paul notably quoted Exodus 9:16 during his discussion of God’s sovereign election in Romans 9. We can observe how the apostle uses that verse by reading its surrounding context:
And not only so, but also when Rebekah had conceived children by one man, our forefather Isaac, though they were not yet born and had done nothing either good or bad—in order that God’s purpose of election might continue, not because of works but because of him who calls—she was told, “The older will serve the younger.” As it is written, “Jacob I loved, but Esau I hated.”
What shall we say then? Is there injustice on God’s part? By no means! For he says to Moses, “I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion.” So then it depends not on human will or exertion, but on God, who has mercy. For the Scripture says to Pharaoh, “For this very purpose I have raised you up, that I might show my power in you, and that my name might be proclaimed in all the earth.” So then he has mercy on whomever he wills, and he hardens whomever he wills.Romans 9:10-18
Verse 18 has a tendency to leave us asking our original question: but why does God harden whomever He wills? Thankfully, Paul gives us an answer to that question, even if we may not see it right away:
You will say to me then, “Why does he still find fault? For who can resist his will?” But who are you, O man, to answer back to God? Will what is molded say to its molder, “Why have you made me like this?” Has the potter no right over the clay, to make out of the same lump one vessel for honorable use and another for dishonorable use? What if God, desiring to show his wrath and to make known his power, has endured with much patience vessels of wrath prepared for destruction, in order to make known the riches of his glory for vessels of mercy, which he has prepared beforehand for glory—even us whom he has called, not from the Jews only but also from the Gentiles?Romans 9:19-24
For all the controversies surrounding Romans 9, this passage is not difficult to understand; it is just difficult to accept. The famous quote attributed to Mark Twain applies perfectly here: “It ain’t the parts of the Bible that I can’t understand that bother me, it’s the parts that I do understand.”
In Isaiah 64, the prophet cast his hope of salvation upon God by saying, “you are our Father; we are the clay, and you are the potter; we are all the work of your hand” (v. 8). In that context, calling God the potter and us the clay receives significantly less controversy, yet Paul’s use of the metaphor is controversial because he calls some of “vessels of wrath” and others “vessels of mercy.”
You see, Paul is clearly saying here that some people are vessels of God’s wrath “prepared for destruction,” so that through them, God may further display the riches of His glory to those whom He has created to be vessels of His mercy.
Is that too intense?
Take a deep breath, and let’s talk about God’s glory for a moment.
I believe that John Piper is right to call God’s glory the radiance of His perfections. It is the outward display of God’s nature and attributes. We behold God’s glory whenever we rightly behold who He is. Thus, he notes that God’s glory is not “one divine attribute among others.” Instead, it is the display of all of His attributes. God’s glory is the revealing of His love, His grace, His wisdom, His kindness, His righteousness, His justice, His wrath, His jealousy, His mercy, His patience, His holiness, etc. “Not just one of these excellencies. All of them.” This includes God’s wrath and His justice.
Now read Romans 9:19-24 again.
God hardens some, as He did with Pharaoh, to be vessels of His wrath in order to display the riches of His glory to those who are His vessels of mercy. Through Pharaoh, God was and is still showing His people the horrors of His wrath, which we too justly deserve, so that we can more clearly see the beauty of His mercy, which He gives to us by grace through His Son. In other words, God is revealing to all that He is the LORD, Yahweh.
Toward the end of writing on this very topic, Piper notes:
I have not removed a mystery; I have stated a mystery. God makes the choice to treat one with mercy and one with hardening unconditionally. Nothing in any person provides a criterion for one being hardened and another receiving mercy. The distinction lies in the will of God. The distinction lies not in man. Yet those who are hardened are truly guilty and truly deserve judgment for the rebellious condition of their hearts. Their own consciences will justly condemn them. If they perish, they will perish for real sin and real guilt. How God freely hardens and yet preserves human accountability, we are not told.
Rather than attempting to resolve this mystery that is beyond our finite comprehension, we should look upon the obstinacy of Pharaoh and cry out for God’s mercy in the name of Christ, pleading to be rescued from our sin. Let us, indeed, flee from the wrath to come and take shelter under the wings of Christ Jesus our Lord, for in Him the Judge of all the earth is also our heavenly Father.
 John Piper, Providence, 44.
 Piper, Providence, 45.
 Piper, Providence, 443-444.