The religious tradition that begins with Judaism focuses more than most religions on things to come. The attention is often on what God will do in the future. A promise is made to Abraham, another to Moses, about what will happen--the people, the promised land--and (since Hebrew has no present tense in the Indo-European sense) the name of God can be translated as "I will be what I will be." This yearning for the "not yet" led to the expectation of a messiah, whose coming would mean peace and universal reconciliation.
Christians said that Jesus was this messiah, but since the world we live in is plainly not reconciled, Christians believe in a second coming, when with Christ's return the world will finally know reconciliation and peace.
And of course this expectation of something yet to come led to Islam, with Muhammad as the final prophet. But it didn't stop there: Shi'a Islam expects the return of the "hidden Imam," and Baha'is claim that Bahaullah is the prophet who succeeded all others.
There are examples of this concern for future deliverance in other religions--Mahayana Buddhism speaks of the Maitreya, the Buddha who is to come--but the expectation that new prophets and messiahs will arise is especially prominent in the Judeo-Christian tradition, leading, for Jews, to Sabbatai Zevi in the seventeenth century, and, among Christians, to Joseph Smith and Mormonism, and to Sun Myung Moon and the Unification Church. Once this mechanism comes into play, there seems to be no end to it. New prophets and messiahs arise, some claiming to be final, and the claim is rejected by believers in the previous final revelation.
The Christian claim, in this apparently unending chain, is radically different, and the radicalism heads in two directions. On the one hand, Christians alone claim that Jesus not only points to the divine, but is divine, of one nature with God. On the other, there is the thorough self-emptying and the complete humanity of Jesus Christ (see Philippians 2:5-11). A total identification with both the human and the divine raises some uncomfortable questions about Christianity's relationship with other religions, including the other Abrahamic ones.
Jews and Muslims find the Christian claim that Jesus is divine impossible. It seems blasphemous to claim that divinity could be so intimately implicated in human flesh and blood, which, after all, is created and therefore radically inferior to the …