(John 17:17 ESV) 17 “Sanctify them in the truth; your word is truth.”
“Sanctify” means to make holy. But that’s not a particularly helpful translation. The NET Bible translators comment —
The Greek word translated set…apart (ἁγιάζω, hagiazo) [or “sanctify” or “make holy”] is used here in its normal sense of being dedicated, consecrated, or set apart. The sphere in which the disciples are to be set apart is in the truth. In John 3:21 the idea of “practicing” (Grk “doing”) the truth was introduced; in John 8:32 Jesus told some of his hearers that if they continued in his word they would truly be his disciples, and would know the truth, and the truth would make them free. These disciples who are with Jesus now for the Farewell Discourse have continued in his word (except for Judas Iscariot, who has departed), and they do know the truth about who Jesus is and why he has come into the world (John 17:8). Thus Jesus can ask the Father to set them apart in this truth as he himself is set apart, so that they might carry on his mission in the world after his departure (note the following verse).
Jesus prays that the disciples will be kept separate from the world. Jesus is not of the world, and neither should they be. Rather, the gospel should transform them into people no longer of the world but dedicated to Jesus.
(John 17:18 ESV) 18 “As you sent me into the world, so I have sent them into the world.”
This is so they can continue the mission of Jesus. God sent Jesus to bring the truth to the world. The disciples are to continue that mission. Even though they are to be separate from the world, they must remain in the world in order to transform the world.
(John 17:19 ESV) 19 And for their sake I consecrate myself, that they also may be sanctified in truth.”
“Consecrate” is the same Greek word as “sanctify,” but used in a different sense. The NET Bible translators explain —
There is in fact a Johannine wordplay here based on slightly different meanings for the Greek verb translated set apart (ἁγιάζω, hagiazo). In the sense it was used in John 10:36 of Jesus and in John 17:17 and here to refer to the disciples, it means to set apart in the sense that prophets (cf. Jer 1:5) and priests (Exo 40:13, Lev 8:30, and 2Ch 5:11) were consecrated (or set apart) to perform their tasks. But when Jesus speaks of setting himself
apart (consecrating or dedicating himself) on behalf of the disciples here in John 17:19 the meaning is closer to the consecration of a sacrificial animal (Deu 15:19). Jesus is “setting himself apart,” i.e., dedicating himself, to do the will of the Father, that is, to go to the cross on the disciples’ behalf (and of course on behalf of their successors as well).
Jesus will be sanctified, but not merely by being dedicated to a particular, God-given task. He will be sanctified as a sacrifice.
The goal of the sacrifice is that the disciples will be “sanctified in truth,” that is, set apart or dedicated to the mission of bringing the truth to the world. Jesus’ must sacrifice himself so that this can happen.
(John 17:20-21 ESV) 20 “I do not ask for these only, but also for those who will believe in me through their word, 21 that they may all be one, just as you, Father, are in me, and I in you, that they also may be in us, so that the world may believe that you have sent me.”
This is a climactic passage, combining themes from throughout John into a simple conclusion.
First, what Jesus is doing is not merely for those disciples present at this meal. It’s for all who believe. Jesus is speaking in cosmic terms. He’s speaking of the millions who will be impacted by his mission for millennia.
That’s true of most of what Jesus has already said (which is why John recorded the rest of his discourse), and so we must understand that Jesus is underscoring this prayer for particular emphasis. Everything he says on the eve of his crucifixion is extremely important, but this is even more so. Pay attention!
He prays for unity of his followers. He wants all his disciples, present and future, to be united in the same sense that he and God are united. Imagine that!
Beyond that, he prays that his disciples themselves be united with him and God — just as they are united with each other.
This is a prayer for theosis — the transformation of a disciple into the image of Christ. But it’s more than that. He’s praying for the theosis of the church. It’s not that individual Christians be united with God; it’s that the entire body of Christ, all disciples, be united with each other and with God and with Jesus.
He’s not speaking of going into our closets and praying so hard that we are individually joined with God. We must be joined with each other, too. This is about the formation of community in the unique, Spirit-empowered way that only comes from God.
Why? “So that the world may believe that you have sent me.” How will the world come to faith in Jesus? By the world seeing his disciples united with each other, with God, and with Jesus.
What would this look like?