The heart of the mystery (that we may not fully understand) is that God’s glory is seen in him having mercy on some and passing over others. Biblically, God is always the author of our salvation (“preparing” men for glory), we are always the authors of our damnation (“preparing” themselves for judgment). God’s glory is displayed— whether in his mercy to the elect, or in his judgment to objects of wrath. Since neither deserved any mercy, God cannot be charged with injustice.
Even when God has the right to exercise his judgment and wrath, how does he deal with those who rebel against him? (v.22)
"Dear God, I’m reminded that you are the one who shapes and molds us. Help me recognise that I am not my own, but I am yours, and you have a purpose for me. Help me surrender to your hands, and to trust your plan for my life. While there is much I don’t understand, Lord— grant me humility and patience in the process of you shaping me into a vessel for your kingdom and your glory. I ask in Jesus’ name, Amen."
The gospel was preached to both Jews and Gentiles, but it was being accepted by far more Gentiles than Jews. The Gentiles did not have God’s law, did not know God, yet they were being made right with God. Why? Because they were coming in faith. In contrast, the Jews tried to get right with God the wrong way— by relying on human effort to keep the law. They certainly had enthusiasm, but it was misdirected zeal, keeping them from understanding righteousness had been provided through faith in Jesus Christ.
What must zeal be based on? (v.2)
"Dear Lord, thank you for your salvation and your righteousness freely given through faith. Grant me the simplicity of faith in the finished work of Christ; but to never lose a zeal for knowing you deeper and more. And help me to be passionate about making you known to those around me who have yet to know of your salvation. In Jesus’ name I pray, Amen."
Faith knows we don’t need to do anything to be righteous. You don’t need to go up to heaven to bring Christ down (Christ has already come in the flesh). You don’t need to deal with your own sins in death (Christ has already been resurrected). Salvation comes from trusting Christ, and it is within easy reach. God will never fail to provide righteousness to those who believe.