An email conversation with my mother regarding the upcoming birth of my Jewish nephew has got me thinking about the relationship of Christianity to non-Christians in the faith of Abraham. I know that there is magisterial teaching on these questions, but I'm just musing this morning.
Perhaps many Jews would object to this, but it seems to me that a Christian is a peculiar sort of Jew. After all, we do what Jews do: we follow the Law and worship at the Temple. For us this is not the historical law or the physical Temple. We keep the Law as it has been received in its prophetic interpretation down to and including the historical Jesus. We worship within the eschatological Temple that is the sacrificed and risen Body of Christ. Therefore, when I meet a Jew, I don't see someone from a different religion but someone of the same religion in a different concept of time. We are both Jews, one a member of the Israel of history, the other a member of the Israel of transcendent time, the end times, the ultimate horizon, the eschaton.
I believe that this is sound and demonstrable Biblical teaching deriving especially from the later prophets, St. John, St. Paul, and Revelation, and if it wasn't two days before Christmas for which three different Sunday-length homilies have to be given in three days, I might have time to point some of this out.
Islam is a lot harder for me, and I admit that I have an unresolved internal tension when I think about it. It seems to me that you have to face the question: Did the angel Gabriel reveal the Qur'an to Muhammad (peace be upon him) or not? If one consents to this proposition, then the only reasonable thing is to surrender to God and become a Muslim right now. If one denies that the Qur'an came from Gabriel, doesn't this invalidate Islam altogether and throw out the faith of nearly a quarter of the people on earth? Is there a way out of this seemingly binary problem?
Of course, if what I say about Christianity being an eschatological religion is accepted in a certain way, then the faith/fulness of Jesus Christ is still a more recent revelation of God than the Qur'an. After all, the Resurrection is the definitive and constitutive sign of the end times, and it has reached back into history and grabbed us.