He is the vine and we are the branches. We are meant to bear "fruit of the vine and the work of human hands" which he raises up and transforms - making it something worthy of his wedding feast. He changes this fruit and work into his precious Blood offering it as the Cup of the New Covenant without which we have no life in us. The 3rd Edition to the Roman Missal, with the new translation of text, helps us also see that as the Vine, He is also the source of our fruitfulness and our work which He accepts from us - meaning everything that is most important about our life must be ordered around prayer:
Blessed are you, Lord God of all creation,
for through your goodness
we have received the wine we offer you:
fruit of the vine and work of human hands
it will become our spiritual drink.
This new translation of this prayer of the priest, which will go into usage this November, indicates in the Christian life, everything is grace, everything is a gift from God through Christ. Our work and our fruitfulness are not ultimately the products of our self-reliance and competency. These too are gifts, graces for which to give thanks.
By the Father's generosity to us in his Son, He raises our whole being to participate in the very life of the Holy Trinity, makes us capable being fruitful, of doing something beautiful for God. We call such participation divine life "grace" because it is a pure gift merited for us by Jesus' death on the Cross. Christ died that we might have this new life. Through his wounds, God's life flows into our hearts when we say "yes" by faith. Because it comes through the Risen Lord, the sanctifying life of grace sets us apart as Christ-like, uniting us to Him, and allowing us to draw from Him everything we need for holiness:
"The life of grace is, then, a conformity to Christ. But it is not only a question here of an external imitation, but of a sharing in the very life of Christ. Thus Christ is not only the pattern, the archetype according to which we ought to reform our soul; he is also the source from which alone the life of grace can be unfolded in us." Jean Danielou, God and the Ways of Knowing, trans. Walter Roberts, San Francisco: Ignatius Press (1957, reprint 2003), 200.
Jean Danielou helps us see the connection between imitation of Christ, sharing his life and the life of prayer. Christian life is not simply about external conformity to socially accepted behaviors - in other words, it is not primarily about a observing a moral code and cultural conventions. These things are part of the Christian life, but secondary to a deeper interior reality, a reality which transcends conventions and constantly rises above moral norms. Our external behaviors are meant to be the fruit of something unfolding deep within - signs of a new vital principle being born within.
True imitation of Christ is first an interior reality where the movements of one's own heart participate in the movements of Christ's heart. It is the movement of Christ's own life in the Christian which makes the believer fruitful. It is by the life of Christ in us by faith that we have fruit of the earth and work of our hands worthy of being offered in a manner that is acceptable to God.
How does our faith make the life of Christ fruitful in such a wonderful way? Grace is given in prayer. Prayer is the branch cleaving to the Vine to draw its life, to draw forth grace. Prayer humbly seeks from the Lord what is needed to be fruitful, and in Him even our prayer itself becomes good fruit. He then draws everything that is good, noble and true in this to Himself transforming the fruit of the vine and work of our hands into his own blood.
Christ renews this union of life and love at every Mass. Through his priestly and creative action, he makes our lives, our work, our fruitfulness part of his blood offering, glorifying the Father and extending his salvation to the world. In his wisdom and goodness, He does this through our frail humanity He already infused with his life. He pours our life into His Blood. He pours his Blood into our lives. It is the sacred banquet, mystical wedding feast, to which all true prayer is ordered and from which all real prayer comes.