Expectation of the Messiah and his Spirit
The Messiah's characteristics are revealed above all in the "Servant songs." These songs proclaim the meaning of Jesus' Passion and show how he will pour out the Holy Spirit to give life to the many: not as an outsider, but by embracing our "form as slave." Taking our death upon himself, he can communicate to us his own Spirit of life.
Source: Catechism of the Catholic Church (Vatican.va)