15:2

He cuts off every branch in me that bears no fruit, while every branch that does bear fruit he trims clean so that it will be even more fruitful.


We should not regard this as a proof that true believers may fall away. it is part of the viticultural picture, and the point could not be made without it. The emphasis here is on bearing fruit.

In a vineyard fruitfulness is not just desirable; it is imperative; that is the whole point of the vineyard; it is what the vineyard is for. Pruning is resorted to to ensure that this takes place. Left to itself a vine will produce a good deal of unproductive growth. For maximum fruitfulness extensive pruning in essential.

This is a suggestive figure for the Christian life. The fruit of Christian service is never the result of allowing the natural energies and inclinations to run riot. "Trims clean" more literally "cleans" where we might have expected "prunes," shows that we have now moved into the spiritual sphere. the interest is in what happens with people rather than with vines. The action of the father is such as to cleanse his people so that they will live fruitful lives.

The Gospel According to John, Leon Morris p. 594-595