Followers know Father through believing in Jesus. This requires a two-fold explanation; how do Jesus and His Father relate, and how do/should Jesus’ followers participate in this relationship? The latter is the focus of Ch.15, the second stage in this affection-full farewell discourse.
vv.1-8 function metaphorically; Jesus is the vine, and his followers must be attached to him while submitting to pruning. Pruning results in fruit-bearing.
vv.9-16 expounds vv.1-8, by exampling Jesus’ relationship with the Father for the disciples; by emphasising obedience and sacrifice; and by applying fruit-bearing. Structural links such as, remaining, fruitfulness, and prayerful-fruitfulness, further accents this connection.
Notice here the covenantal-discontinuity through vv.1-16. Jesus is the vine, Jesus’ servants are friends and have direct mediated access to the Father.
15:18-16:4 shows the expectancy of a fruit-bearing, vine-remaining follower who mirrors the rejected Jesus, is persecuted by ‘the world,’ and is being prepared for the kingdom. However, as throughout the farewell discourse, the counsellor will assure and secure such a follower on this path. This section is exceptionally Trinitarian.
Notice finally, the relational paradigm flow from Jesus and His Father, to Jesus and His followers, to His followers and each other. These pieces climax in the following chapters.