One must remember that Paul also wrote Roman 11:16-26. An individual's salvation has always been a matter of faith (i.e. Hebrews chapter 11) and the determinative factor as to whether a branch is cut off from the Olive tree or grafted in (see also John 3:16-18).
Contrary to the Replacement Theology of Preterism and Roman Catholicism, God has not simply abandoned the Jews (as a people) for their lack of faith.
Romans 9:1 I say the truth in Christ, I lie not, my conscience also bearing me witness in the Holy Ghost, 2 That I have great heaviness and continual sorrow in my heart. 3 For I could wish that myself were accursed from Christ for my brethren, my kinsmen according to the flesh: 4 Who are Israelites; to whom pertaineth the adoption, and the glory, and the covenants, and the giving of the law, and the service of God, and the promises; 5 Whose are the fathers, and of whom as concerning the flesh Christ came, who is over all, God blessed for ever. Amen.
Romans 3:1 What advantage then hath the Jew? or what profit is there of circumcision? 2 Much every way: chiefly, because that unto them were committed the oracles of God. 3 For what if some did not believe? shall their unbelief make the faith of God without effect? 4 God forbid: yea, let God be true, but every man a liar; as it is written, That thou mightest be justified in thy sayings, and mightest overcome when thou art judged.
I think of Christianity as the Prodigal Son who came home and Judaism as the Son who refuses to come into the celebration for the time being.