Traditional Jews expect a literal Messiah, the son of David, who will do many of the things that Christians expect Jesus to do upon His return. At that time, passages such as Isaiah 2:1-4 or Isaiah 11 will be fulfilled; see also Jeremiah 23:5-6.
According to Moses Maimonides (1135-1204), the great codifier and organizer of Jewish laws and beliefs, this is how the Messiah will be known:
If a king will arise from the House of David who is learned in Torah and observant of the mitzvot [the Torah’s commandments], as prescribed by the written law and the oral law, as David his ancestor was, and will compel all of Israel to walk in [the way of the Torah] and reinforce the breaches [in its observance]; and fight the wars of G-d, we may, with assurance, consider him the Messiah.
If he succeeds in the above, builds the Temple in its place, and gathers the dispersed of Israel, he is definitely the Messiah.
If he did not succeed to this degree or he was killed, he surely is not [the redeemer] promised by the Torah. [Rather,] he should be considered as all the other proper and complete kings of the Davidic dynasty who died. G-d only caused him to arise in order to test the many, as [Daniel 11:35] states; “and some of the wise men will stumble, to try them, to refine, and to clarify until the appointed time, because the set time is in the future.
The Messiah, according to Maimonides, whose view is considered authoritative by most traditional Jews, will not be a miracle worker and he will certainly not die and then rise from the dead. Instead, he will be an extraordinarily gifted human being who will lead Israel and the nations back to God.
There is a tradition dating back to the Talmud that mentions a second Messianic figure, called the Messiah son of Joseph, although the origins of this belief are very difficult to trace. According to some traditions, he will only come if the Jewish people are not yet worthy of Messiah son of David. (These figures are called Messiah ben David and Messiah ben Yoseph; traditional Jews say Moshiach rather than Messiah.) He will perform many of the Messianic functions before getting cut down in battle in the last great war, at which point Messiah son of David will raise him from the dead, perform the remaining Messianic functions, and establish God’s kingdom on the earth. His death, however, is not viewed in vicarious, substitutionary terms—like the death of Jesus for our sins—and so this Messiah is a suffering Messiah but not a redeeming Messiah.
There are many mystical beliefs associated with the coming of the Messiah, along with the belief that in every generation there is a potential Messiah waiting to be revealed. Thus it is that some of the most influential Jews of past generations—especially those steeped in mysticism—have been viewed after their death as the potential Messiahs of their respective generations, but their respective generations were not considered worthy and so this potential Messiah was never revealed.
This again underscores the traditional Jewish belief that the Messiah will be fully human, also explaining Talmudic traditions that state that if the people of Israel were to observe one Sabbath (or, according to other traditions, two consecutive Sabbaths), the Messiah would be revealed. (In other words, he is here in every generation but not recognized as Messiah and not revealed in his full glory or potential.) In keeping with this, and as formulated by Maimonides, traditional Jews pray and confess daily, “I believe in perfect faith in the coming of the Messiah, and even though he delay, I will wait for him every day that he will come.”
Conservative Jews still expect a literal Messiah, but Reform Judaism, in its classical form, has put a greater emphasis on the Messianic era that will be realized through the mission of the Jewish people and the self-improvement of the human race. This is in keeping with the somewhat humanistic, anti-supernatural outlook of Reform Judaism but is certainly out of step with historic Jewish beliefs.
It should be remembered, however, that the majority of Jews today—both in America and worldwide—are not deeply religious and therefore belief in a Messiah is not something on the minds of a great many Jews. For them, the concept of God must become central in their lives before they will give much thought to the idea of a Messiah.