In Abrahamic religions, the Messiah (Hebrew: מָשִׁיחַ, translit. māšîaḥ), Christ (Greek: Χριστός, translit. Khristós), or Al-Masih (Arabic: المسيح, ISO 233: mahdī) is the one chosen to lead the world and thereby save it.
The concepts of Moshiach, Messianism, and Messianic Age grew from Isaiah's writings (4:2 & ch 11) during the latter half of the 8th century BCE. The term comes from the Hebrew verb meaning "to apply oil to," to anoint. In the Hebrew Bible, Israel's kings were sometimes called God's "messiah" -- God's anointed one. A moshiach (messiah) could also be an anointed high priest or prophet. Messiahs did not even need to descend from Jacob, as the Hebrew Bible refers to Cyrus the Great, king of Persia, as a messiah for his decree to rebuild the Jerusalem Temple.
In Judaism, the Jewish Messiah, hamashiach (המשיח, "the anointed one"), often referred to as "King Messiah" (מלך המשיח, melekh hamashiach), is expected to descend from King David and accomplish the unification of the twelve tribes, into a re-established nation. The Jerusalem Temple's rebuilding will usher in a Messianic Age of global peace.