“Remain in me”
Though the Father prunes (literally cleanses) the living wood in order to produce maximum fruit (15:2), this is not the basis of our being in Jesus – what makes us clean (the same word used in v.2) is Jesus’s saving word i.e. the revelation he had brought to them which will culminate in his death for our sins (3; 13:10). The key thing, therefore, is to remain in him, so that his life can go out through us (4).
.
The word remain is the Greek word meno which has the sense of to be but with the added note of permanence i.e. to dwell, to abide, to remain there. The importance of this word is seen by its repetition – meno occurs three times in verse 4 alone, and then a further seven times in verses 5-10. So the Christian needs to live continuously in a close relationship with Jesus, in the confidence that Jesus and the Father live in us and make their abode in us (4; 14:20; 14:23).
.
Once again, Jesus declares that he is the vine, and this time spells out that we are like branches in that vine, through which his life will flow. There can be no fruit at all without remaining in Jesus, for he alone is the source of life (4-5). But the corollary of this is that whoever does remain in him will certainly bear his fruit.