6 It is not as though the word of God had failed. For not all Israelites truly belong to Israel, 7and not all of Abraham’s children are his true descendants; but ‘It is through Isaac that descendants shall be named after you.’ 8This means that it is not the children of the flesh who are the children of God, but the children of the promise are counted as descendants. 9For this is what the promise said, ‘About this time I will return and Sarah shall have a son.’ 10Nor is that all; something similar happened to Rebecca when she had conceived children by one husband, our ancestor Isaac. 11Even before they had been born or had done anything good or bad (so that God’s purpose of election might continue, 12not by works but by his call) she was told, ‘The elder shall serve the younger.’ 13As it is written,
‘I have loved Jacob,
but I have hated Esau.’
14 What then are we to say? Is there injustice on God’s part? By no means! 15For he says to Moses,
‘I will have mercy on whom I have mercy,
and I will have compassion on whom I have compassion.’
16So it depends not on human will or exertion, but on God who shows mercy. 17For the scripture says to Pharaoh, ‘I have raised you up for the very purpose of showing my power in you, so that my name may be proclaimed in all the earth.’ 18So then he has mercy on whomsoever he chooses, and he hardens the heart of whomsoever he chooses.
God’s Wrath and Mercy
19 You will say to me then, ‘Why then does he still find fault? For who can resist his will?’ 20But who indeed are you, a human being, to argue with God? Will what is moulded say to the one who moulds it, ‘Why have you made me like this?’ 21Has the potter no right over the clay, to make out of the same lump one object for special use and another for ordinary use? 22What if God, desiring to show his wrath and to make known his power, has endured with much patience the objects of wrath that are made for destruction; 23and what if he has done so in order to make known the riches of his glory for the objects of mercy, which he has prepared beforehand for glory— 24including us whom he has called, not from the Jews only but also from the Gentiles?--Romans 9: 6-24 NRSV http://bible.oremus.org/?passage=Romans+9
EDIT: I should add that this passage does not necessarily entail that God predestines some people not to be saved. For a little later on Paul says:
25 So that you may not claim to be wiser than you are, brothers and sisters, I want you to understand this mystery: a hardening has come upon part of Israel, until the full number of the Gentiles has come in. 26And so all Israel will be saved; as it is written,--Romans 11: 25-32 NRSV [emphasis mine, and footnotes ommitted], http://bible.oremus.org/?passage=Romans+11
‘Out of Zion will come the Deliverer;
he will banish ungodliness from Jacob.’
27 ‘And this is my covenant with them,
when I take away their sins.’
28As regards the gospel they are enemies of God for your sake; but as regards election they are beloved, for the sake of their ancestors; 29for the gifts and the calling of God are irrevocable. 30Just as you were once disobedient to God but have now received mercy because of their disobedience, 31so they have now been disobedient in order that, by the mercy shown to you, they too may now receive mercy. 32For God has imprisoned all in disobedience so that he may be merciful to all.
Note that the last sentence prima facie implies universalism; i.e., that all will be saved.