Romans 9:19-21 — Thou wilt say then unto me, Why doth He yet find fault? For who hath resisted His will?
Nay but, O man, who art thou that repliest against God? Shall the thing formed say to Him that formed it, Why hast Thou made me thus?
Hath not the potter power over the clay, of the same lump to make one vessel unto honour, and another unto dishonour?
Why does God hold anyone accountable for a hardened heart?
His will = His counsel which rules over human action as opposed to His desire. Man can resist the desire of God but not His determined will.
Verse 20 shows that to ask the question is to misunderstand the relation between God and Man. Surely your turning of things upside down shall be esteemed as the potter's clay: for shall the work say of him that made it, He made me not? or shall the thing framed say of him that framed it, He had no understanding? (Isaiah 29:16).
You say, "That sounds terrible — that God has the right to take the clay and make one man a sinner and another a righteous man!" But he does not say that. God makes no man a sinner. Remembe this: God takes the clay as He finds it, and the "clay" here is man who is already a sinner. "Thou art the potter, we are the clay." Paul is not talking about the creation of man. God created him good, holy, and righteous, but the clay that the apostle is talking about here is sinful clay. Out of that clay every man stands alike. Every man is a sinner, every man deserves judgment. God has a right to pick out one man from that mass and have mercy upon him, and let the other man go if He wants to. Paul is not talking here about God creating man in sin. God did no such thing. — Romans: The Gospel of God's Grace, by Alvin J. McClain, page 182-183.
Surely the potter has complete power over the clay, but God exercises this power in accordance with the highest moral principles — His own. In Israel's case He used it to display His mercy; in Pharaoh's to display His wrath upon sin, making of the one a "vessel unto honor," and of the other a "vessel unto dishonor."
Thus, rather than debating the issue, we are wiser to place ourselves in the hands of the Master Potter, beseeching Him to make of us vessels unto honor. Indeed, this is especially appropriate where the believer in Christ is concerned, for the Potter is not yet finished with us. Thus the Apostle declares in 2 Timothy 2:20-21 that if we purge ourselves from spiritual uncleanness he will make of us "vessels unto honor, sanctified, and meet for the Master's use … " — The Epistle of Paul to the Romans, by Cornelius R. Stam, page 231-232.