Salvation depends on God's mercy. Romans 9:15-16, “For He says to Moses, ‘I will have mercy on whomever I will have mercy, and I will have compassion on whomever I will have compassion.’ So then it is not of him who wills, nor of him who runs, but of God who shows mercy.” It's not up to man's free will, because his will is bound. Sinners choose sin.
Jacob and Esau are an example. Romans 9:11-13, “For the children not yet being born, nor having done any good or evil, that the purpose of God according to election might stand, not of works but of Him who calls, it was said to her, ‘The older shall serve the younger.’ As it is written, ‘Jacob I have loved, but Esau I have hated.’” One was hated and the other was loved before they were born. It was not based on their works. Both were born God hating and gospel rejecting sinners, unwilling to turn to Christ because of the curse [Gen 2:17; Gen 3:8; Eph 2:1-3]. God hated Esau by allowing him to choose his own way, which is the way of all flesh. God loved Jacob by drawing him to Himself irresistibly.
This is justice. (1) God owes salvation to no one. (2) He has a right to show blood-bought mercy to anyone. (3) He does not reject anyone who comes to Him.
Secondly, God hardens people. Romans 9:18, “So then, He shows mercy to those He wants to, and He hardens those He wants to harden.” This must make us fear.
We cannot be casual about the gospel, as if I'll get to it later. We do not know if God will harden us, like most who hear the gospel, by allowing us to continue in proud rebellion without softening our hearts! The gospel is the sun, we are the clay, and without the water of sovereign mercy, we hear the gospel resistantly and refuse Him. The result is God justly withdraws conviction and power, so that we see nothing and feel nothing of His glory or our danger!
Oh, how frightful this is. Immediately trust Christ, or you may never want Him later. The truth you know now may lose its luster, and you perish without conviction in false assurance!
Thirdly, God is willing to show His wrath. Romans 9:22, “And what if God, desiring to display His wrath and to make His power known, endured with much patience objects of wrath ready for destruction?” He wants His justice and power to be known for all eternity, as He punishes sinners. He will cast them into hell prepared for the Devil, and forever the smoke of their torment will arise [Rev 19:3].
Oh, fearful God! Who will challenge You? God is not all love. He has hatred and justice. He has heaven and hell. He is true, righteous, and He fulfills His warnings. He is to be feared, and sin is to be fled from. Run to the Savior. These are God's terms!
Fourthly, God makes a people for Himself. Romans 9:26, “And it will be in the place where they were told, you are not My people, there they will be called sons of the living God.”
He controls the future. He calls us by the gospel, and we come to Christ, seeing our sin as filthy, His wrath is hot, and our Savior fully satisfied the terms of divine justice [vs24]! He laid down His life for our freedom and welcomes us to receive grace and mercy. Grace to cover our sins, and mercy to help us sin no more. Grace to enjoy His gifts, and mercy to alleviate what we deserve. Grace and mercy are for all of our days, as we follow the Lamb. The grace of sonship and merciful deliverance from sin's bondage. Oh, how wonderful it is to walk with God - safe from hell, holy, and heaven bound! How wonderful it is to be assured that you are His, and He is yours!
Finally, pursue it by faith. Romans 9:30-32, “What should we say then? Gentiles, who did not pursue righteousness, have obtained righteousness—namely the righteousness that comes from faith. But Israel, pursuing the law for righteousness, has not achieved the righteousness of the law. Why is that? Because they did not pursue it by faith, but as if it were by works. They stumbled over the stumbling stone.”
Don't try to earn acceptance with God. Believe it is something God gives you by faith in Christ. Look to the Son of God, and trust Him to be why God's gracious to you… Not because of works you've done, but His perfect work as a substitute. Look to Him and say, "I trust Christ. Therefore, I have the whole of salvation. I believe the gospel. Therefore, I'm elect!"