Ezekiel reveals God's promise to gather all the Jewish tribes into one nation. Apart from the historical situation which the prophet is referring to, we hear in his words themes which are common whenever the Old Testament speaks of a promised Messiah, namely the theme of unity and the theme of a new covenant.

In contrast to the Old Testament vision of the unity of the Jewish people, St John has a more universal vision. Jesus died, not "for this nation only, but to gather into one all the scattered people of God." This vision could only come to reality through Jesus, who established the new covenant in his blood on the cross. It is echoed in our Third Eucharistic Prayer: "In your compassion, O merciful Father, gather to yourself all your children scattered throughout the world."

Jesus explains his mission on earth in various ways, among them the work of the Good Shepherd: "The Son of Man has come to seek out and to save what was lost" (Lk. 19:10).