The Word of God became flesh from and in our Lady two thousand years ago. It was an action both of God and her that consisted in her free consent to Christ’s life and death for us. She “heard” the Word in its most radical form which is to take it into herself and live it. The Word took flesh in her and from her. By taking it in in such a way, she became the Word.
To “know” the Word then is not to know an idea or come to a conclusion. When Joseph Ratzinger describes this he takes on the topic of the existence itself of God and the meaning of God as “living:”
“What does it mean when we call this God a living God? It means that this God is not a conclusion we have reached by thinking, which we now offer to others in the certainty of our own perception and understanding… When we talk of the living God, it means: This God shows himself to us; he looks out from eternity into time and puts himself into relationship with us. We cannot define him in whatever way we like. He has ‘defined’ himself and stands now before us as our Lord, over us and in our midst. This self-revelation of God, by virtue of which he is not our conception but our Lord, rightly stands, therefore, in the center of our Creed.”
And the “center” of the creed is not an idea or concept we profess, but the personal “Yes” that actually incarnates the Word again in us at this particular moment in time and space. That is to say, Christmas actually takes place again as truly as it did two thousand years ago. Ratzinger remarked: “the heart of all our creeds is our Yes to Jesus Christ: ‘By the power of the Holy Spirit he was born of the Virgin Mary.’ We genuflect at this clause, because at this point the heavens, the veil behind which God is secluded, are swept aside, and the mystery touches us directly. The distant God becomes our God, becomes ‘Emmanuel – God with us’ (Mt. 1, 23)”
But this calls for an explanation. It is a command performance to revamp our understanding of the metaphysical anthropology of the human person. It is the call to put the reality of the Word of God as keystone to epistemological realism. It is the call to pay serious attention to the indication of Cardinal Marc Ouellet at the last Synod on the Word of God held in October 2008: “the dogmatic Constitution Dei Verbum marked a real turning point in the manner of dealing with Divine Revelation. Instead of privileging, as before, the noetic dimension of truths to be believed in, the Council Fathers emphasized the dynamic and dialogic accent  of Revelation as personal self-communication of God. Thus they put down the bases for a more vivid encounter and dialogue between God who calls and His people who respond.”
By “noetic dimension of truths to be believed in” Ouellet is saying that the human person does not “know” primarily by concepts and ideas, but by a consciousness that is the fruit of a total personal experience, like faith. The conceptual way of knowing is a reflection on a direct experience and consciousness of the self that takes place in the response “Yes” that is the sign of the act of self-transcendence. This is what Ratzinger means by saying that “heart of all our creeds is our Yes to Jesus Christ.” The human person is constitutively a relation, not a thing-in-itself, which Aristotle called “substance.” “Substance” is a category fabricated by the abstractive power of the mind to immaterialize what is perceived in the senses. It is not false, but it is already a distortion of the way reality is. Ultimately, it is not real. The only reality is the Word of God Himself and our conformity to this Word by our becoming it. When we say “Yes” to it, we make the gift of receiving it obediently into us and forming a covenant with it (Him).
Even more astoundingly, we find here what Ratzinger had written about the meaning of Revelation and Faith as removing the “veil” of the “vel” in “Revelation.” Notice that he says: “We genuflect at this clause, because at this point the heavens, the veil behind which God is secluded, are swept aside, the mystery touches us directly.” It touches us directly because we become the flesh of the Word (total self-gift to the Father and to us) and experience ourselves as “other Christs.” This can happen only when we make the act of faith – the “Yes” – as our Lady did. And this is what is meant by “Blessed is she who believed.” She became divinized as “blessed” because of her act of self-gift. And each of us must become the mother who engendered Him by hearing the word of God and doing it: “My mother and my brothers are those who hear the word of God and do it” (Lk. 8, 20-21).
The “veil” of the vel in “Revelation” is removed by saying “Yes.” The invisibility of God is removed. God is known as “Living” because He lives in me in that I am He. This is the principal problem of our time. We know about God, but we do not know God. He is the result of a conclusion, but not a direct experience that can only take place within myself and of myself. At best, we have reduced God to a “hobby.” We are self-sufficient and independent. God is not needed “having absolutely nothing to do.”
The supreme implication of the above is considerable. It says that Revelation takes place only when there is an act of faith. Ratzinger wrote: “The receiving subject is always also a part of the concept of ‘revelation.’ Where there is no one to perceive ‘revelation,’ no re-vel-ation has occurred, because no veil has been removed. By definition, revelation requires a someone who apprehends it.” This can sound terribly subjectivistic unless one remembers that we are not dealing with “noetic” knowing but as Ouellet said it above: “the dynamic and dialogic accent  of Revelation as personal self-communication of God.” It is an understanding of the human person in terms of revelation and faith, not as the result of sensible perception and abstraction as in “rational animal” or “individual substance of a rational nature.”
Pastorally and scientifically, this means that without prayer, one cannot rightly do theology because one does not know God. Without personal prayer that is experience of Jesus Christ, one cannot “know” the God that no one has ever seen.
This is the meaning of Christmas as Eschatology.