As is evident, all of Christ's preaching and his entire messianic mission was directed to gathering the flock. It is not merely a case of so many individual hearers, followers, and imitators. It is rather an assembly, which is expressed in Aramaic as kehala, and in Hebrew gahal, corresponding to the Greek ekklesia. The Greek word derives from a verb meaning "to call" (the Greek translation of "a call" is klesis). This etymological derivation gives us to understand that, as in the old covenant God had "called" his people Israel, so Christ calls the new People of God, choosing and seeking its members from among all peoples. He draws them to himself and gathers them around him by means of the word of the Gospel and by the redemptive power of the paschal mystery. This divine power, manifested definitively in Christ's resurrection, will confirm the words once spoken to Peter: "Upon this rock I will build my Church" (Mt 16:18), that is, the new assembly of the kingdom of God.
The Church-ecclesia-assembly receives from Christ the new commandment. "I give you a new commandment, that you love one another, as I have loved you.... By this all will know that you are my disciples..." (Jn 13:34; cf. Jn 15:12). It is certain that the "assembly-Church" receives from Christ also its external structure (of which we shall treat in the near future). But its essential value is the communion with Christ himself. It is he who gathers together the Church; it is he who builds it constantly as his Body (cf. Eph 4:12), as the kingdom of God on the universal level. "They will come from east and west and sit at table (with Abraham, Isaac and Jacob) in the kingdom of God" (cf. Lk 13:28-29).