Let's open our Bibles to Romans 9;14-16.

As the righteous Sovereign over all, God is not unjust to grant mercy to some and to harden others, because all deserve His judgment

As the righteous Sovereign over all, it is outrageous to think that God could treat anyone unjustly (9:14)To raise the question of fairness presupposes that you have rights and that your rights are being violatedWe all have sinned without excuse against GodHis justice would only bring us what we deservedMatt 20:1-16 Am I not allowed to do what I choose with what belongs to me?As the righteous Sovereign over all, God is free to show mercy to whomever He wishes (9:15-16)Moses boldly asked God to show him His glory in Exo 33:18God declared He would proclaim the name of the Lord before MosesIt included this statement, I will have mercy on whom I have mercy, and I will have compassion on whom I have compassionGod's glory is displayed by His freedom to show mercy and compassion on whomever He wishesThomas Schreiner: No human being deserves God's mercyWe all justly deserve condemnationAs the righteous Sovereign over all, God is free to harden whom He wishes, to display His glory (9:17-18)God is not unjust to raise up a proud sinner on the stage of world history and use him for God's greater purpose of demonstrating His power and causing His name to be widely proclaimedGod is not unjust to grant mercy to some to display the glory of His grace, and to harden others to display the glory of His righteous judgmentLuke 18:13, God, be merciful to me, a sinner!