42. "By this all will know that you are my disciples, if you have love for one another" (Jn 13:35). If we have truly contemplated the face of Christ, dear Brothers and Sisters, our pastoral planning will necessarily be inspired by the "new commandment" which he gave us: "Love one another, as I have loved you" (Jn 13:34).

This is the other important area in which there has to be commitment and planning on the part of the universal Church and the particular Churches: the domain of communion (koinonia), which embodies and reveals the very essence of the mystery of the Church. Communion is the fruit and demonstration of that love which springs from the heart of the Eternal Father and is poured out upon us through the Spirit which Jesus gives us (cf. Rom 5:5), to make us all "one heart and one soul" (Acts 4:32). It is in building this communion of love that the Church appears as "sacrament", as the "sign and instrument of intimate union with God and of the unity of the human race".²⁶

The Lord's words on this point are too precise for us to diminish their import. Many things are necessary for the Church's journey through history, not least in this new century; but without charity (agape), all will be in vain. It is again the Apostle Paul who in the hymn to love reminds us: even if we speak the tongues of men and of angels, and if we have faith "to move mountains", but are without love, all will come to "nothing" (cf. 1 Cor 13:2). Love is truly the "heart" of the Church, as was well understood by Saint Thérèse of Lisieux, whom I proclaimed a Doctor of the Church precisely because she is an expert in the scientia amoris: "I understood that the Church had a Heart and that this Heart was aflame with Love. I understood that Love alone stirred the members of the Church to act... I understood that Love encompassed all vocations, that Love was everything".²⁷