Calvin completely missed the message in Romans 9. Paul is writing about God choosing to give mercy to the Gentiles. The Jews are the vessel for wrath and the Gentiles are the vessel for honor. Please read the lower portion carefully as I have pasted the two scriptures in Romans 9 together to make it more clear.
“What if God, although willing to demonstrate His wrath and to make His power known, endured with much patience vessels of wrath prepared for destruction? And He did so to make known the riches of His glory upon vessels of mercy, which He prepared beforehand for glory, even us, whom He also called, not from among Jews only, but also from among Gentiles. As He says also in Hosea, "I WILL CALL THOSE WHO WERE NOT MY PEOPLE, ' MY PEOPLE,' AND HER WHO WAS NOT BELOVED, ' BELOVED.'" " AND IT SHALL BE THAT IN THE PLACE WHERE IT WAS SAID TO THEM, ' YOU ARE NOT MY PEOPLE,' THERE THEY SHALL BE CALLED SONS OF THE LIVING GOD." Isaiah cries out concerning Israel, " THOUGH THE NUMBER OF THE SONS OF ISRAEL BE LIKE THE SAND OF THE SEA, IT IS THE REMNANT THAT WILL BE SAVED; FOR THE LORD WILL EXECUTE HIS WORD ON THE EARTH, THOROUGHLY AND QUICKLY." And just as Isaiah foretold, " UNLESS THE LORD OF SABAOTH HAD LEFT TO US A POSTERITY, WE WOULD HAVE BECOME LIKE SODOM, AND WOULD HAVE RESEMBLED GOMORRAH." What shall we say then? That Gentiles, who did not pursue righteousness, attained righteousness, even the righteousness which is by faith; but Israel, pursuing a law of righteousness, did not arrive at that law. Why? Because they did not pursue it by faith, but as though it were by works. They stumbled over the stumbling stone,”
(Notice how this compares to “For He says to Moses, "I WILL HAVE MERCY ON WHOM I HAVE MERCY, AND I WILL HAVE COMPASSION ON WHOM I HAVE COMPASSION." So then it does not depend on the man who wills or the man who runs, but on God who has mercy.”)