Our encounter with Jesus Christ is itself dynamic, a process of growth in faith and holiness. Even when there are dramatic moments of great conversion, these must be integrated into our hearts and lives. The Gospels give us this pattern, both in themselves, and (one might add) in how they are used liturgically:
Reading the Gospel accounts, we see how Jesus’ own humanity appears in all its uniqueness precisely with regard to the word of God. In his perfect humanity he does the will of the Father at all times; Jesus hears his voice and obeys it with his entire being; he knows the Father and he keeps his word (cf. Jn 8:55); he speaks to us of what the Father has told him (cf. Jn 12:50); “I have given them the words which you gave me” (Jn 17:8). Jesus thus shows that he is the divine Logos which is given to us, but at the same time the new Adam, the true man, who unfailingly does not his own will but that of the Father. He “increased in wisdom and in stature, and in favour with God and man” (Lk 2:52). In a perfect way, he hears, embodies and communicates to us the word of God (cf. Lk 5:1). (12)
Just as preparatory revelation leads to the definitive revelation of Christ, so too the Gospels reveal Christ to us progressively, from His Incarnation and birth, to His preaching and miracles, to His Passion and Resurrection. This paschal mystery is the pinnacle of Christ's own mission:
Jesus’ mission is ultimately fulfilled in the paschal mystery: here we find ourselves before the “word of the cross” (1 Cor 1:18). The word is muted; it becomes mortal silence, for it has “spoken” exhaustively, holding back nothing of what it had to tell us.... In this great mystery Jesus is revealed as the word of the new and everlasting covenant: divine freedom and human freedom have definitively met in his crucified flesh... (12)
Further, just as He Himself illumines the whole of creation, just so His Passion illumines for us the whole of His life:
In the most luminous mystery of the resurrection, this silence of the word is shown in its authentic and definitive meaning. Christ, the incarnate, crucified and risen Word of God, is Lord of all things; he is the victor, the Pantocrator, and so all things are gathered up forever in him (cf. Eph 1:10). Christ is thus “the light of the world” (Jn 8:12), the light which “shines in the darkness” (Jn 1:5) and which the darkness has not overcome (cf. Jn 1:5). (12)
Since "Human salvation is the reason underlying everything" (9), Easter is the definitive statement (Word) of that meaning. The early Fathers sometimes described the significance of Easter as the "fulcrum" of all time. Pope Benedict is making a similar claim here, morally rather than chronologically:
...Christ’s victory over death took place through the creative power of the word of God. This divine power brings hope and joy: this, in a word, is the liberating content of the paschal revelation. At Easter, God reveals himself and the power of the trinitarian love which shatters the baneful powers of evil and death. (13)
Only perfect love fulfills perfectly our inherent longing for communion.
Because Easter has this overarching clarity and depth of meaning for all the rest of creation, it must be accepted as definitive revelation. Since Jesus truly is God Himself, what more of God could He reveal? What greater obedience or victory could He enact? Therefore the Church has taught since the beginning that revelation is complete ("perfected") in Christ:
Indeed, as the Fathers noted during the Synod, the “uniqueness of Christianity is manifested in the event which is Jesus Christ, the culmination of revelation, the fulfilment of God’s promises and the mediator of the encounter between man and God. He who ‘has made God known’ (Jn 1:18) is the one, definitive word given to mankind” (14; he also here cites St. Paul, Dei Verbum, and St. John of the Cross).
Very briefly, the exhortation then draws out the implications of this fact for eschatological truth (the Lord we meet after death is the same Lord we already meet and love - or not - in this life) and for private revelations (increase faith and devotion, and sometimes have a prophetic character, but don't add anything to Scripture or Tradition), before turning to the Holy Spirit's role.