This is a passage of great importance.
What is the imagery of grafting about? What have the Jews cut themselves off from? What have the Gentiles of this passage been grafted onto?
The passage implies an expectation (though it is stated only as a possibility) - the expectation that Jews would eventually be "grafted back," indeed that they provide better material for engrafting than the Gentiles. This expectation - the expectation that eventually the Jews would convert to Christianity - became a double-edged sword for the Jews in Christendom. How so, do you think?
SOME MAJOR QUESTIONS
Having now read most of the Book of Romans, let's consider how Paul is answering (or whether he is answering) the following questions that might have been posed to him:
1) Doesn't Hebrew Scripture prophesy a messiah who will be a Messiah to the Jews only?
2) Jesus himself observed the Law of the Jews, and you, Paul, appear to observe it too. Shouldn't Gentiles who accept the teachings of Jesus then also accept the Law Jesus followed?
3) You say Jesus's death has allowed the Old Law to be replaced. But many passages in Hebrew Scripture teach that the Law is eternal and must be obeyed forever. For example, Deut. 11:1 - "You shall therefore love the Lord your God, and keep his charge, his statutes, his ordinances, and his commandments always." Did not Jesus himself say, "Think not that I have come to abolish the law and the prophets; I have come not to abolish them but to fulfill them. For truly, I say unto you, till heaven and earth pass away, not an iota, not a dot, will pass from the law until all is accomplished" (Matt. 5: 17-18).
4) Why have most of the Jews refused to accept Jesus as the messiah?
5) If there is salvation only through Jesus, what is the status of the patriarchs of the Old Testament? Are they among the damned?