In the Old Testament the Biblical prophecies state:

Before the time of the messiah, there shall be war and suffering (Ezekiel 38:16), the messiah will bring about the political and spiritual redemption of the Jewish people by bringing Jews back to Israel and restoring Jerusalem (Isaiah 11:11-12; Jeremiah 23:8; 30:3; Hosea 3:4-5). He will establish a government in Israel that will be the center of all world government, both for Jews and gentiles (Isaiah 2:2-4; 11:10; 42:1). He will rebuild the Temple and re-establish its worship (Jeremiah 33:18). He will restore the religious court system of Israel and establish Jewish law as the law of the land (Jeremiah 33:15).

Jews do not believe that Jesus was the messiah because JESUS DID NONE OF THESE THINGS! Over 100 people have made claims to being messiah, most of them fulfilled at least one or two of the Old Testament prophecies, but Jesus fulfilled none of them. He just cruised up and announced himself like the Jews were going to say "Oh, ok total stranger who fulfilled none of the prophecies, you can be our most sacred figure for no real reason at all besides you saying so!".

So how did Christians justify calling Jesus the messiah? By bullshitting. Seriously. They said things like "Well, Jesus's body is Israel, and since all men must follow him, this satisfies the requirement that he make Israel the leading nation". This is why Jesus was put to death and boils in shit in hell for eternity. I suggest you all stop being antisemitic; it's against the law.