"I am the vine, you are the branches." In this way our Lord speaks of the vital union between himself and the disciple brought about by his Paschal Mystery. As life flows into the branch in virtue of its union with the vine and enables it to bear fruit, so, too, do life and fruitfulness flow in and through us from our communion with Jesus. And just as a branch will wither and die if cut off from the vine, so, too, are we dependent upon our Lord for life and for the good works we wish to accomplish in his name. "Apart from me you can do nothing."
When you have a moment, read Romans 6: 3-11. This is St. Paul's primary teaching on Baptism, where he speaks at verse five of growing together with Christ, an image derived from the practice of grafting a branch onto a stem. His point is the same as that of Jesus: we must be "grafted" onto the Lord if we are to receive the life he came to give. Such "grafting" occurs at our Baptism. Of course, this begs the question: what attention am I paying to this relationship? Even I know that a plant needs tending if it is to live.
Striking in this regard are the references made by Jesus to pruning. He is the vine, yes, but his Heavenly Father is the vinedresser. In love and mercy our Father tends the vine, and prunes away from its branches that which is not healthy so that it will bear the fruit he intends. This pruning takes place by means of the Word which Jesus speaks. In other words, our fruitfulness as disciples will derive first and foremost from allowing ourselves to be "pruned" by attentiveness to the Word of God and its call to conversion. To live as branches grafted on to the vine that is Jesus necessitates prayerful attentiveness to Sacred Scripture, so that we might hear and heed its call to personal repentance. This listening leads necessarily to the sacraments, where the grace of mercy enables the conversion to which the Word calls us.
Pruning. "Ouch!" Yes, letting go of that which is not healthy for our souls can hurt at first, and the pain felt will be in proportion to the degree of our attachment. But what is at stake is the fullness of life that comes from our union with Christ. Let's not hesitate to allow the Vinedresser to do his work.