Here, it is Jesus himself who promises that he will ask the Father to send his Spirit, defined as "another Paraclete" (Jn 14: 16), a Greek word that is equivalent to the Latin "ad-vocatus", an advocate-defender. The first Paraclete is in fact the Incarnate Son who came to defend man from the accuser by antonomasia, who is Satan. At the moment when Christ, his mission fulfilled, returns to the Father, he sends the Spirit as Defender and Consoler to remain with believers for ever, dwelling within them. Thus, through the mediation of the Son and of the Holy Spirit, an intimate relationship of reciprocity is established between God the Father and the disciples: "I am in my Father, and you in me, and I in you", Jesus says (Jn 14: 20). However, all this depends on one condition which Christ imposes clearly at the beginning: "If you love me" (Jn 14: 15), and which he repeats at the end: "He who obeys the commandments he has from me is the man who loves me; and he who loves me will be loved by my Father. I too will love him and reveal myself to him" (Jn 14: 21). Without love for Jesus, which is expressed in the observance of his commandments, the person is excluded from the Trinitarian movement and begins to withdraw into himself, losing the ability to receive and to communicate God.
[Pope Benedict, homily 27 April 2008]