No matter how you read it, the end of Romans 11 is tough stuff:

25 I do not want you to be ignorant of this mystery, brothers, so that you may not be conceited: Israel has experienced a hardening in part until the full number of the Gentiles has come in. 26 And so all Israel will be saved, as it is written:

 “The deliverer will come from Zion; he will turn godlessness away from Jacob. 27 And this is my covenant with them when I take away their sins.”

 28 As far as the gospel is concerned, they are enemies on your account; but as far as election is concerned, they are loved on account of the patriarchs, 29 for God’s gifts and his call are irrevocable. 30 Just as you who were at one time disobedient to God have now received mercy as a result of their disobedience, 31 so they too have now become disobedient in order that they too may now receive mercy as a result of God’s mercy to you. 32 For God has bound all men over to disobedience so that he may have mercy on them all.

V. 28 is the focus: when it comes to the gospel preaching of redemption in Christ, the unbelieving zealous Jewish opponents of the gospel are “enemies” but that does not rule out their election. God’s gifts and God’s call – his gracious election of Israel from the time of Abraham and Jacob – are irrevocable. God must remain true to his promises to Israel, the nation.

The gospel Paul preaches elicits rejection, sometimes by the very people the gospel was designed to redeem – Israel. (There is a debate about the meaning of “Israel” and some think it refers to the scattered, dispersed, northern kingdom.)