What is the definition of Messiah according to Judaism Christianity and Islam?

Answer 1

All three religions define the concept of the Messiah differently.

Judaism:
Judaism holds that the Messiah is to be an Earthly King, who will rule on Earth in accordance with the Divine Will and not an incarnation or union with God. Some of the particulars include:

• The Messiah will reign over Earth as an actual Righteous King on Earth (Jeremiah 23:5-6)
  
• The Messiah or God will rebuild the Temple in Jerusalem and make the services operate properly (Ezekiel 37:26-28).
  
• All Jews, living or dead, will be gathered back to the Land of Israel (Isaiah 43:5-6)
• The Messiah's ascendance to power will usher in an era of world peace, and end all hatred, oppression, suffering and disease. As it says: "Nation shall not lift up sword against nation, neither shall man learn war anymore." (Isaiah 2:4)
• Because of the righteousness of the Messiah universal knowledge of the God of Israel will spread across the world, which will unite humanity as one. As it says: "God will be King over all the world -- on that day, God will be One and His Name will be One" (Zechariah 14:9)
• The Messiah must have direct paternal lineage from King David via Solomon and Rehoboam (Genesis 49:10 and Isaiah 11:1)
• Foreigners will help rebuild Israel and help serve it (Isaiah 60:10)
• The Natural Order will be abrogated, with a cessation of all predation and violence within the animal kingdom (Isaiah 11:6-8) and with the sun never setting (Isaiah 60:19-20)
  
• The Messiah will lead the Jewish people to full Torah observance. Any person who comes in an effort to abrogate laws, alter laws, or add new laws is clearly not the Messiah, but a false prophet. (Deut. 13:1-4)
• The Dead will rise from their graves and resume life among the living (Isaiah 26:19)
• Death shall be abolished for eternal life (Daniel 12:2)

Christianity:
Christianity holds that Jesus is the Christ or Messiah and was sent to the entire world. Because of the Doctrine of the Trinity, Christianity holds that Jesus is consubstantial (made of the same essence) as God the Father and has been in existence as long as God the Father has been. The following include other key attributes about the Christian conception of the Messiah:

• The purpose of the Messiah was to be a blood sacrifice of atonement to counter Original Sin and, therefore, provide people a way of achieving eternal life in heaven.
  
• Since the Messiah had to be born without sin in order to be a pure blood sacrifice, the Messiah had to be a person born through no act of sex, e.g. a virgin birth.
  
• The Messiah was to face bodily torture as foretold in Isaiah 53.
  
• The Messiah is to have a second coming in which he fulfills the remaining prophecies in the Old and New Testaments and confronts the Antichrist, which is a personage who leads the demonic forces.
  
• The Messiah is supposed to oppose the Temple structure because the Temple venerates physicality as opposed to spirituality.
  
• The purpose of the Messiah is to be hidden and vague to prevent those unworthy of understanding the meaning of life and ascension to heaven.
  

Islam:
Islamic tradition holds that Jesus, the son of Mary, was a Prophet and the Messiah sent to the Children of Israel, and that he will return to Earth at the End of Days, along with the Mahdi, who is another key personage, and defeat the Dajjal or Antichrist. In Islam, the Messiah is a human being who cannot die and has not died. He is currently in occultation, where he hides his identity until the moment when the End of Days when he returns into the open.