Maybe you weren't told, but many ancient rabbinic sources understood Isaiah 53 as referring to the Messiah. Here are quotations from some of them:
Babylonian Talmud: "The Messiah --what is his name?...The Rabbis say, The Leper Scholar, as it is said, `surely he has borne our griefs and carried our sorrows: yet we did esteem him a leper, smitten of God and afflicted...'" (Sanhedrin 98b)
Midrash Ruth Rabbah: "Another explanation (of Ruth ii.14): -- He is speaking of king Messiah; `Come hither,' draw near to the throne; `and eat of the bread,' that is, the bread of the kingdom; `and dip thy morsel in the vinegar,' this refers to his chastisements, as it is said, `But he was wounded for our transgressions, bruised for our iniquities'"
Targum Jonathan: "Behold my servant Messiah shall prosper; he shall be high and increase and be exceedingly strong..."
Zohar: "`He was wounded for our transgressions,' etc....There is in the Garden of Eden a palace called the Palace of the Sons of Sickness; this palace the Messiah then enters, and summons every sickness, every pain, and every chastisement of Israel; they all come and rest upon him. And were it not that he had thus lightened them off Israel and taken them upon himself, there had been no man able to bear Israel's chastisements for the transgression of the law: and this is that which is written, `Surely our sicknesses he hath carried.'"
Rabbi Moses Maimonides: "What is the manner of Messiah's advent....there shall rise up one of whom none have known before, and signs and wonders which they shall see performed by him will be the proofs of his true origin; for the Almighty, where he declares to us his mind upon this matter, says, `Behold a man whose name is the Branch, and he shall branch forth out of his place' (Zech. 6:12). And Isaiah speaks similarly of the time when he shall appear, without father or mother or family being known, He came up as a sucker before him, and as a root out of dry earth, etc....in the words of Isaiah, when describing the manner in which kings will harken to him, At him kings will shut their mouth; for that which had not been told them have they seen, and that which they had not heard they have perceived." (From the Letter to the South (Yemen), quoted in The Fifty-third Chapter of Isaiah According to the Jewish Interpreters, Ktav Publishing House, 1969, Volume 2, pages 374-5)
Rabbi Mosheh Kohen Ibn Crispin: This rabbi described those who interpret Isaiah 53 as referring to Israel as those: "having forsaken the knowledge of our Teachers, and inclined after the `stubbornness of their own hearts,' and of their own opinion, I am pleased to interpret it, in accordance with the teaching of our Rabbis, of the King Messiah....This prophecy was delivered by Isaiah at the divine command for the purpose of making known to us something about the nature of the future Messiah, who is to come and deliver Israel, and his life from the day when he arrives at discretion until his advent as a redeemer, in order that if anyone should arise claiming to be himself the Messiah, we may reflect, and look to see whether we can observe in him any resemblance to the traits described here; if there is any such resemblance, then we may believe that he is the Messiah our righteousness; but if not, we cannot do so." (From his commentary on Isaiah, quoted in The Fifty-third Chapter of Isaiah According to the Jewish Interpreters, Ktav Publishing House, 1969, Volume 2, pages 99-114.)
The Two-Messiah Theory
When one studies rabbinic views of the Messiah one finds something very interesting. Many ancient rabbis spoke of two Messiahs, one who was the "Son of David" and another who was the "Son of Joseph." Though one can find the sufferings of Messiah attributed to the sufferings of the Davidic Messiah in many rabbinic writings, often a second Messiah is posited, the "Son of Joseph" or "Son of Ephraim," who is the one who suffers while the Davidic Messiah conquers. The rabbis struggled with Biblical portraits of a suffering Messiah, as found in Isaiah 53 and other places, and portraits of a conquering Messiah, also found in the Hebrew Bible. They posited two Messiahs, but could it not also be reasonable to believe there is just one Messiah but two aspects of his mission, a suffering aspect and a conquering aspect?
The eminent scholar Raphael Patai, who "taught Hebrew at the Hebrew University of Jerusalem" and served as Professor of Anthropology at Dropsie University,1said this of the two-messiah theory:
"When the death of the Messiah became an established tenet in Talmudic times, this was felt to be irreconcilable with the belief in the Messiah as Redeemer who would usher in the blissful millennium of the Messianic Age. The dilemma was solved by splitting the person of the Messiah in two: one of them, called Messiah ben Joseph, was to raise the armies of Israel against their enemies, and, after many victories and miracles, would fall victim Gog and Magog. The other, Messiah ben David, will come after him (in some legends will bring him back to life, which psychologically hints at the identity of the two), and will lead Israel to the ultimate victory, the triumph, and the Messianic era of bliss."2
There is only one Messiah, but there are two comings and two aspects of his ministry. The Messiah came the first time to provide atonement for sin. He is now expanding his kingdom and conquering the Gentiles, not by the sword, but by preaching. (In this century alone over 50,000,000 Chinese have come to faith in the God of Israel through Jesus, even while being persecuted.) Messiah's Kingdom is growing tremendously among the Koreans and in Africa and South America. Many earthly rulers bow down before Messiah Jesus. One day he will return to judge the earth and to bring in his Kingdom in all its fullness. Know him now as your sin-bearer and bow before him today as your King, and when he returns you will not need to fear the judgement, because he came to receive the judgement in the place of those who trust him.
1. Patai, Raphael, The Messiah Texts, Avon Books, © 1979, p. vii
2. Ibid., p. 166