15:1-17 This allegory is at the heart of Jesus’s farewell discourse to the disciples. The OT used the vineyard or vine as a symbol for Israel, God’s covenant people, especially in two “vineyard songs” (Is 5:1-7; 27:2-6). However, Israel’s failure to produce fruit resulted in divine judgment. Jesus, by contrast, is the true vine, and his followers are to remain in him and produce much fruit for God.
15:1 I am the true vine is the last of Jesus’s seven “I am” sayings in John’s Gospel (see note at 6:35,48). “True” contrasts Jesus with OT Israel (see note at 15:1-17). Joseph was called a “fruitful vine” in Gn 49:22. The reference to the Father as the gardener harks back to Isaiah’s first vineyard song, where God is depicted as tending his vineyard, only to be rewarded with worthless grapes (Is 5:1-7; cp. Ps 80:8-9).
15:2 To ensure maximal fruit production, the divine vineyard keeper removes dead branches and prunes all the others (Heb 6:7-8). In John’s Gospel, Judas the betrayer is an example of the former scenario (Jn 13:10-11). Peter, who denied Jesus three times, is an example of the latter (18:15-18,25-27; 21:15-19).
15:4,5,8 The repeated reference to fruit underscores that fruitfulness is God’s primary creative (Gn 1:11-12,22,28) and redemptive purpose (Jn 15:8,16). The OT prophets envisioned a time when God’s people would “blossom and bloom and fill the whole world with fruit” (Is 27:6; cp. Hs 14:4-8).
15:6 This verse echoes Ezk 15:1-8, where a barren vine is said to be fit only for burning. Fire is a common symbol for divine judgment (Is 30:27; 66:24; Mt 3:12; 5:22; 18:8; 25:41; see note at Jn 15:2).
15:16 In first-century Palestine, disciples typically took the initiative in attaching themselves to a particular rabbi, not vice versa. As a well-known dictum declared, “Provide yourself with a teacher.” Jesus broke with this custom and called his own disciples. Appointed recalls the OT description of God’s appointment of Abraham (Gn 17:5; cp. Rm 4:17), the ordination of Levites (Nm 8:10), and Moses’s commissioning of Joshua (Nm 27:18).
15:18-16:33 This final major unit in Jesus’s farewell discourse deals with the world’s hostility toward him and his followers and with the future ministry of the Holy Spirit.
15:19-23 Jesus’s disciples have no control over how their message is received. People’s responses will be determined by their attitude toward Jesus. The words in v. 23 belie those who claim to love God but will not accept Jesus. They would not be guilty of sin does not mean the world would be perfect. Rather it stresses the world’s guilt since Jesus has come.
15:25 Jesus declared that the Jews’ hatred of him fulfilled OT Scripture, specifically Ps 69:4 (cp. Ps 35:19). This Davidic psalm depicts a righteous sufferer who is zealous for God but is persecuted by God’s enemies for no reason. Thus Jesus saw David’s experiences as a prefiguration of the hatred and rejection he suffered.
15:27 The call for Jesus’s followers to serve as his witnesses recalls OT prophetic literature, where God’s end-time people are called his “witnesses” to the nation (Is 43:10-12; 44:8). In the NT, believers are promised the Spirit’s help in times of persecution (Mt 10:20; Mk 13:11; Lk 12:12), and the Spirit played a vital part in the church’s mission (Ac 1:8; cp. Lk 24:48; Ac 5:32; 6:10).