"I have other sheep that are not of this fold; I must bring them also, and they will heed my voice. So there will be one flock, one shepherd" (Jn 10: 16).
John repeated the same thing after the Sanhedrin had decided to kill Jesus, when Caiaphas said that it would be better for the people that one man die for them rather than the entire nation perish. John recognized these words of Caiaphas as prophetic, adding: "Jesus should die for the nation, and not for the nation only, but to gather into one the children of God who are scattered abroad" (11: 52).
The relationship between the Cross and unity is revealed: the Cross is the price of unity. Above all, however, it is the universal horizon of Jesus' action that emerges.
If, in his prophecy about the shepherd, Ezekiel was aiming to restore unity among the dispersed tribes of Israel (cf. Ez 34: 22-24), here it is a question not only of the unification of a dispersed Israel but of the unification of all the children of God, of humanity - of the Church of Jews and of pagans.
Jesus' mission concerns all humanity. Therefore, the Church is given responsibility for all humanity, so that it may recognize God, the God who for all of us was made man in Jesus Christ, suffered, died and was raised.
The Church must never be satisfied with the ranks of those whom she has reached at a certain point or say that others are fine as they are: Muslims, Hindus and so forth. The Church can never retreat comfortably to within the limits of her own environment. She is charged with universal solicitude; she must be concerned with and for one and all.
[Pope Benedict, homily 7 May 2006]