When you truly feel equal love for all beings, when your heart has expanded so much that it embraces the whole of creation, you will certainly not feel like giving up this or that. You will simply drop off from secular life as a ripe fruit drops from the branch of a tree. You will feel that the whole world is your home.
- Ramana Maharshi
Jesus was the Jewish Maharshi ("great seer"). He transcended the particular to feel equal love for all beings, dropping off from secular life as a ripe fruit drops from the branch of a tree. Individual Jews can achieve redemption from galut as surely as individual Hindus can achieve liberation from samsara. Jesus was part of the prophetic tradition, perhaps its culmination - but he was not the messiah.
The messiah is not just an enlightened being who feels the whole world is his home; the messiah, in the Jewish tradition, makes the whole world home for everyone. Converting the whole world to Christianity cannot make the world Christ-like, as surely as declaring the state of Israel Zion cannot end the galut. Salvation is not collective; like damnation, it is tailored to the individual.
St. Paul writes: "There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus." It is a beautiful vision; but Jesus still considered himself a Jew, and arguably so did Paul himself. Greeks still consider themselves Greeks, and aren't particularly fond of Jews at that.
Paul inspired the Christian tradition of forcing the evidence to fit the claim. If Jews aren't yet one in Christ Jesus, an Inquisition can fix the matter. Greeks of course can still keep their Greek identity - as long as they pay lip-service to the universal Christ. By no means did Paul or Jesus intend this charade, but history is beyond anyone's control - even the Jews, despite what anti-Semites claim.
I am a Jew for Jesus in the same sense that Hindus who recognize Buddha as an incarnation of Vishnu are "Hindus for Buddha." A Samaritan can be good without ceasing to be a Samaritan; a Jew can be universally-minded without ceasing to be a Jew. The universal is not only accessible from the vantage of the particular, it is only accessible from the vantage of the particular.
A Christian once told me that he didn't like Jews for their "us and them" mentality. Of course, the Christian "us" are those who reject the "us and them" mentality by embracing Christ; the heathen "them" are those who reject that rejection by retaining their own image of God. The word Islam means both peace and submission - and there's the rub for Abrahamic universalism.
A scattering of enlightened souls see that all is one. An army of hypocrites say that all is one, as long as everyone becomes one by converting to their religion. Christ is a way out of exile, but not the way. I will feel the whole world is my home not by making everyone like me, but by seeing in them my likeness. If I never reach that point it is because not everyone can be the Jewish Maharshi.