Messiah is our peace, who made both groups into one, and broke down the barrier of the dividing wall [of hostility] … that in Himself [by dying on the stake] He might make the two into “one new man” (Ephesians 2:14-15).
Redeemed Gentiles received a divine mandate to lovingly draw the Jews to their Messiah. "For if their rejection [of Messiah] be the reconciliation of the world, what will their acceptance be but life from the dead?"
Israel is a “thriving olive tree”, having originated with Abraham, Isaac, and Jacob. “If the root be holy, the branches are too.” Gentiles are to remember that it is not they who supports the root, but the root supports them.
If the wild olive is grafted into the cultivated olive tree, the cultivated olive will run to wildness. Paul was well aware of the risk of grafting the Gentiles into the holy olive tree because it was “contrary to nature.”