18 Therefore He has mercy on whom He wills, and whom He wills He hardens.
Verse 18 is the conclusion to Paul’s argument about Pharaoh.
18 Therefore [wherefore therefore]
The “therefore” states the principle of verses 14 to 17. The will of God stands above everything. God wills mercy as a principle of grace in His plan.
Divine hardening of Pharaoh is a corollary to Ishmael’s and Esau’s rejection. This underscores the contrast of the two “wills” of human will and God’s will.
He has mercy on whom He wills,
It is God’s choice to whom He gives His mercy because He always acts according to His character and plan (scheme). This statement refers to the Exodus situation of God’s dealing with the nations of Israel and Egypt, not individuals. The place of Israel in God’s plan is the point.
“Whom He wills” expresses God’s sovereignty. He does not have to verify why He does what He does, because no finite human being can make decisions from an eternal perspective—only a finite standpoint.
God’s actions are not arbitrary; His decisions are always consistent with His character.
God does not directly force His will arbitrarily on people to commit sin. He is not the author of evil. He does not solicit people to sin:
Ja 1: 13 Let no one say when he is tempted, “I am tempted by God”; for God cannot be tempted by evil, nor does He Himself tempt anyone.
On the other hand, God will do things to people out of His own sovereignty, which may be the circumstance for their sin. All of our sin is the result of our own sinfulness:
Ja 1: 14 But each one is tempted when he is drawn away by his own desires and enticed.
When we choose to reject God’s will, we will harden in the wrong. We produce a self-judgment, a self-induced misery. God will allow us to go our way but we still operate under our own will. Hardening is not necessarily permanent. We always have the opportunity to repent (Ro 2:4).
Man today values his autonomy. The idea that God is sovereign does not sit well with people. Personal perception of what ought to be is a philosophy built around the self, as if the self were the ultimate authority. If God spoke through the Word of God, then that authority takes precedence over the authority of man. That is a difficult thing for twenty-first-century secularism to grasp. God does not and cannot conform to man’s premises if He is absolute.