Whoever lives in me, as I live in him, bears much fruit. ~Jn 15:5
The passage from the gospel in which the Lord calls himself the vine and his disciples the branches affirms in its own way that, as mediator between God and the human race, the man Christ Jesus is head of the Church and we are his members.
It is beyond dispute that a vine and its branches are of one and the same stock. Since Christ, therefore, possessed a divine nature not shared by ourselves, he became man precisely in order that in his own person there might be a vine of human stock whose branches we could become.
"Dwell in me," said Jesus, "and I will dwell in you."His disciples, however, do not dwell in Christ in the same way as Christ dwells in them. In either case, the benefit is theirs, not his.
If branches are attached to a vine, it is not to confer any advantage on the vine; it is rather that the branches themselves may draw their sustenance from the vine. The vine is attached to the branches to provide them with their vital nourishment, not to receive anything from them.
In the same way Christ’s presence in his disciples and their presence in him both profit the disciples rather than Christ. If a branch is cut off, another can grow from the life-giving root; but once severed from the root no branch can remain alive.
The incarnate Truth goes on to say: "I am the vine, you are the branches. Whoever dwells in me and I in him yields fruit in plenty, because without me you can do nothing." These are words to be weighed and pondered continually.
Someone hearing Jesus say, he yields fruit in plenty, might perhaps think that a branch can bear at least a certain amount of fruit on its own. Our Lord’s words, however, were not: "You can do little without me," but: "You can do nothing."
Little fruit or plenty, there can be neither without him, because without him nothing can be done.
Even if a branch does produce a little fruit, the vinedresser prunes it away so that it may produce more. But if the branch does not remain attached to the vine and draw its life from the root, it can bear no fruit at all.
Now, although Christ could not be the vine if he were not human, he could not offer such a grace to his branches if he were not at the same time divine.
Since without this grace it is impossible to have life and consequently death is the result of one’s free choice, he said: "Whoever does not dwell in me will be thrown away like a branch and will wither, to be gathered in and cast on the fire to burn."
And so the shame incurred by those branches that refuse to dwell in the vine is in direct proportion to the glory they will have if they do remain in him.
"If you dwell in me, said Jesus, and my words dwell in you, you will ask for whatever you desire and it will be yours." Can a person dwelling in Christ desire anything out of harmony with Christ? The very fact that people dwell in their Savior must mean that they have no desire that is opposed to their salvation.
And yet we do indeed desire one thing insofar as we are in Christ, and another insofar as we are still in this world. Because of our sojourn here below, a thought sometimes steals into our ignorant minds to ask for something which cannot be good for us.
But this may not be, if we are dwelling in Christ.
He does what we ask only if it is for our good. To dwell in him, therefore, is to have his words dwelling in us; whatever we desire we shall then ask for, and it will be given us.
~St. Augustine, 354-430