Bearing Fruit. The OT prophets envisioned a time when Israel would “bud and blossom and fill all the world with fruit” (Isa. 27:6; cf. Hos. 14:4–8). What is the “fruit” that the gardener expects from the branches? When chapter 15 is read in context of John 14 it is evident that loving Jesus (vv.15, 21, 23) forms part of the answer. When read in the context of John 13, loving each other (vv.34-35) forms another part of the answer. In the light of the what is understood as the two greatest commandments, “love” is the expected fruit. If so, then the unproductive branches of 15:2 are the people who are in Jesus, in the community of faith, who are not loving, who are not seeking the good of the whole body.
Leon Morris writes : “The part of the Father here is decisive. He watches over the vine and takes action like that of a vinedresser to secure fruitfulness. Every fruitless branch he takes away (cf. Matt. 3:10). 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 is on the bearing of fruit. That is the only reason for growing a vine; as Ezekiel pointed out long before, a vine does not yield timber (Ezek. 15). In a vineyard fruitfulness is not simply desirable; it is imperative; that is the whole point of the vineyard; it is what the vineyard is for. Pruning is resorted to [in order to] ensure that this takes place. Left to itself a vine will produce a good deal of unproductive growth. For maximum fruitfulness extensive pruning is essential.”
The fruit of Christian life is never the result of allowing the natural energies and inclinations to run riot. The verb kathairō has the double meaning of “to prune” and “to cleanse” so that with this verb the Fourth Evangelist can simultaneously evoke agricultural realism and theological truth. Jesus’ words in vv. 3–4a build on this double meaning and equate “cleansing” with staying in relationship to Jesus and his word. Jesus’ abiding in the disciples provides the grounds for their faithfulness to him. These verses recall the foot washing in John 13, where cleansing was also identified as being in relationship with Jesus. The return to the agricultural metaphor in v. 4b reinforces that relationship with Jesus is the key to bearing fruit.
The “fruit” is not defined here, but we are assured that as believers we need to bear fruit. As Stoffregen reminds us: “In another context, Jesus speaks about another way of bearing much fruit, ‘I tell you the truth, unless a kernel of wheat falls to the ground and dies, it remains only a single seed. But if it dies, it produces much fruit’ (12:24). Pruning sounds healthier than dying!” Yet the Christian scriptures are filled with the meaning of the “fruit” that we are to bear. The word fruit, or a variation of it, is used fifty-five times in the New Testament and refers to a variety of results. Each one of the following is considered by God to be fruit: repentance (Matt. 3:8; Luke 13:5-9), practicing the truth to make your Christian identity known in the world (Matt. 7:16-21; Col. 1:10), sanctification and eternal life (Rom 6:22; Phil 1:11), the fruit of the Spirit (Gal 6:22), righteousness/truth (Eph 5:9), answered prayer (John 15:7-8), an offering of money given by believers (Rom. 15:28), and winning unbelievers to Christ (Rom. 1:13).
The action of the Father is such as to cleanse his people so that they will live fruitful lives.
John 15:5 bear much fruit: One of the early Church Fathers was Polycarp of Smyrna. Polycarp is a bit of an odd name. Verse 5 speaks of “much fruit” – karpos polys – leading some to speculate this as the origin of Polycarp’s name: the one who bore much fruit.