John does not teach a replacement theology whereby the church takes the place of Israel. As a closer look at John 15 indicates, it is not believers in Jesus who are depicted as the vine. Rather, the vine is Jesus. Jesus himself is therefore the new Israel, just as he has already been portrayed as the replacement of the temple and the fulfillment of the symbolism of various Jewish festivals. Jesus thus embodies and fulfills God’s true intentions for Israel; he is the paradigmatic vine, the channel through whom God’s blessings flow and who bears much fruit. Indeed, by dying Jesus will prove exceedingly fruitful: “Very truly I tell you, unless a kernel of wheat falls to the ground and dies, it remains only a single seed. But if it dies, it produces many seeds” (12:23–24). The parallel between the fruitfulness of Jesus and that of his disciples, depicted in the present allegory as branches of the vine, is obvious: “This is to my Father’s glory, that you bear much fruit, showing yourselves to be my disciples. . . . I chose you and appointed you so that you might go and bear fruit—fruit that will last” (15:8, 16).
Theologically, then, John’s point is that Jesus now is the new Israel that becomes the focus of God’s plan of salvation, with the implication that faith in Jesus becomes the decisive characteristic for membership among the people of God. Israel, ethnically constrained as God’s chosen people, has been transmuted into the new messianic community, made up of believing Jews and Gentiles, united by their faith in Jesus the Messiah. This does not mean that there no longer remains a place for Jews in the family of God. What it does mean, however, is that Jews must come to God on his terms, not theirs. A paradigm shift has taken place in which faith in Jesus has superseded keeping the Law as the primary religious point of reference. As Paul writes, “Christ is the culmination [telos] of the law” (Rom 10:4): he is its fulfillment and thus replacement (literally, its “end” or “goal”).
Does this mean that Israel as an ethnic group has ceased to be a factor in God’s salvific purposes? This appears to be the implication in certain parts of the New Testament. Thus Paul can call the church “the Israel of God” (Gal 6:16), and Peter is able to apply Old Testament designations of Israel freely to his predominantly Gentile audience (see esp. 1 Pt 1:1; 2:4–10). Yet Paul’s discussion in Romans 9–11 makes clear that God still has a purpose for ethnic Israel. At the present time, his focus has shifted to bringing in the Gentiles, but at the end of salvation history his attention will once again be directed to the Jewish nation. At last, at Christ’s return, the Jews will recognize their Messiah, and “in this way all Israel [not necessarily every single Jew alive at that time, but the nation as a whole as represented by its leadership] will be saved” (Rom 11:26). This excludes all ethnic or religious pride and exalts only the glorious grace of God. For it is faith that constitutes the grounds for salvation, not human merit or ethnicity.
Excerpt from Encountering John.