15 "“I am the true vine, and my Father is the vine dresser. 2 Every branch in me that does not bear fruit he takes away, and every branch that does bear fruit he prunes, that it may bear more fruit. 3 Already you are clean because of the word that I have spoken to you. 4 Abide in me, and I in you. As the branch cannot bear fruit by itself, unless it abides in the vine, neither can you, unless you abide in me. 5 I am the vine; you are the branches. Whoever abides in me and I in him, he it is that bears much fruit, for apart from me you can do nothing. 6 If anyone does not abide in me he is thrown away like a branch and withers; and the branches are gathered, thrown into the fire, and burned."
John 15:1-6
There are two things in particular to notice in relation to the principle of fruitfulness unfolded in these verses. The first is that the undeviating emphasis in Scripture for the bringing forth of life is through death. To the ignorant onlooker, the slashing of the pruning knife seems madness, destroying all the look of the plant. Some of the best-looking and most hopeful parts are sacrificed, cut off. But this is in fact what leads to fruit-bearing. The Vine itself was cut and bled at Calvary, in order that it might fulfil its function in the world. The other thing is that the pruning knife of the Husbandman is the Word itself. It is its self-destroying disciplines that purge our souls and fit us for the business of fruit-bearing in the world. It is when we neglect His Word, and when we refuse to allow it to do its gracious work in the deep places of our spirits that we become rank and wild, and degenerate and unfruitful. It is worth remembering this. So often, believers look for, and hanker after, exhilarating experiences in spiritual life that will lift them up and make them fruitful overnight, when what is needed is a common or garden, honest-to-goodness attitude of obedience to His Word, sitting under it and letting it make men and women of us.
Another way of putting this is given us in 4, 5 - abiding in Christ is the condition of fruitfulness for the branches of the vine. The metaphor is still at this point horticultural. In any grafting operation in which branches are grafted into a tree, there are two main risks - a dry branch may be loosened, or it may run to wood and leaves. The second of these dangers is answered, as we have seen, by the careful pruning of the husbandman's knife. The first is spoken of in the words 'abide in Me'. In the horticultural sense, 'the graft is not only tied to the tree, but the point of juncture is cased in clay or pitch or wax, so as to exclude air, water or any disturbing influence. So also, in the spiritual sense, if the soul and Christ are to be really one, nothing must be allowed to tamper with the attachment'.