The question of fairness arises whenever someone makes a choice to favor one person over another. Paul dealt with the justice of God in doing what He did in this pericope.
"These verses are a detour from the main road of Paul's argument. Paul takes this detour because he knows that his insistence on God's initiative in determining who should be saved and who rejected (see vv. 10-13 especially) will meet with questions and even objections. Appropriately, therefore, Paul reverts to the diatribe style, with its question-and-answer format and references to a dialogue partner, that he has utilized earlier in the letter (see 2:1-3:8; 3:27-31; 6-7)."301
9:14 The apostle first flatly denied the charge that God is unjust. God cannot be unjust because He is God.
9:15 Then he proceeded to refute the charge. When the whole nation of Israel rebelled against God by worshipping the golden calf (Exod. 33), God took the lives of only 3,000 of the rebels. He could have justly slain the whole nation. His mercy caused Him to do something that appeared to be unjust. Likewise in His dealings with Jacob and Esau God blessed Esau greatly as a descendant of Abraham as He did all of Abraham's descendants. Nevertheless He chose to bestow special grace on Jacob.
"The graceof God has been spoken of in this Epistle often before; but not until these chapters is mercynamed; and until mercy is understood, grace cannot be fully appreciated."302
9:16 It is not man's desire or effort that causes God to be merciful but His own sovereign choice. God is under no obligation to show mercy or to extend grace to anyone. If we insist on receiving just treatment from God, what we will get is condemnation (3:23).
9:17 God said He raised Pharaoh up. God had mercifully spared Pharaoh up to the moment when He said these words to him, through six plagues and in spite of his consistent opposition to God. God did not mean that He had created Pharaoh and allowed him to sit on Egypt's throne, though He had done that too. This is clear from Exodus 9:16, which Paul quoted. The NASB translation makes this clear by translating Exodus 9:16, ". . . for this cause I have allowed you to remain."Pharaoh deserved death for his opposition and insolence. However, God would not take his life in the remaining plagues so his continuing opposition and God's victory over him would result in greater glory for God (cf. Josh. 9:9; Ps. 76:10).
Here is another example similar to the one in verse 15 of God not giving people what they deserve but extending mercy to them instead.
9:18 This statement summarizes Paul's point. In chapter 1 the apostle had spoken about the way God gives people over to their own evil desires as a form of punishment for their sins. This is how God hardens people's hearts. In Pharaoh's case we see this working out clearly. God was not unjust because He allowed the hardening process to continue. His justice demanded punishment.
"Neither here nor anywhere else is God said to harden anyone who had not first hardened himself."303
". . . we say boldly, that a believer's heart is not fully yielded to God until it accepts without question, and without demanding softening, this eighteenth verse."304
"God's hardening, then, is an action that renders a person insensitive to God and his word and that, if not reversed, culminates in eternal damnation."305
"God's hardening does not, then, causespiritual insensitivity to the things of God; it maintains people in the state of sin that already characterizes them."306
Paul did not mention the fact that Pharaoh hardened his own heart, which Moses stated in Exodus. Paul's point was simply that God can freely and justly extend mercy or not extend mercy to those who deserve His judgment.
