John 17:17 “Sanctify them in the truth; your word is truth.”
In the last three verses of this second and largest section of what we are calling The Real Lord’s Prayer, Jesus makes his second specific request for his disciples who are with him on that night before his crucifixion.
His first request was for their preservation (verses 11-16). He prayed that the Father would keep them, and specifically that he would keep them from the evil one.
His second request is for their sanctification, or consecration (verses 17-19). In verse 17, he prays that they would be sanctified. Then, in verses 17 and 19, he prays that they would be sanctified “in the truth”. And in verse 18 he states why they need to be sanctified.
The Meaning of Sanctification
To begin with, we need to consider two words that the ESV uses in these verses that are at the very heart of this prayer of the Lord – sanctify (vv17 and 19) and consecrate (v19). Actually, both these words are, in the original, the same word, which is why, for example, the NIV and the AV use the word sanctify on all three occasions.
Now the root idea behind that word sanctify, or consecrate, is a word meaning to separate. When we think of sanctify, I think we instinctively think of moral purity, and while that’s not wrong, it’s not the primary or main meaning of the word. Above all, it means to separate, or to set apart.
In the Old Testament, a person, or a thing, would be set apart for the exclusive possession and service of God, and such a person or thing was said to be sanctified or consecrated. We see this, for example, in the consecration of Aaron and his sons in Exodus 29; the Tabernacle and its furnishings in Exodus 40.
So, first and foremost, Jesus is praying that his disciples be set apart, separated, by God for his exclusive possession and purpose.
Now that is where the moral aspect of purity comes into play; the idea of purity that we naturally think of. You see, if someone is set apart for God and for his purposes then, ideally, that person will only do what God wants, love what God loves, and hate what God hates.
Moral purity is an outworking or fruit of our being separated by and for God. Notice how separation and holiness of life are joined together in Leviticus. “Consecrate yourselves, therefore, and be holy” (11:44; 20:7).
So, Jesus’ prayer for his disciples is, in effect, a two-fold prayer – that they might be set apart for God and set apart from sin.
This understanding of sanctification and consecration may help us see why the ESV chooses to use consecration rather than sanctification when translating the word of Jesus. Usually I am complaining that English translations should be more consistent in their rendering of words from the original language, but here, I can see why the ESV has opted for consecrate, on the part of Jesus, and sanctify, on the part of the disciples.
It’s usually the ESV which gives a more literal, word-for-word translation, while the NIV opts for a dynamic, thought-for-thought rendering. But here, the ESV makes clear a distinction between the situation of the disciples and the Saviour.
Having prayed that the Father might “sanctify” the disciples, in the sense we have been reflecting on, Jesus says that he “consecrates” himself, although the original word is, as we have seen, exactly the same.
You see, the disciples need to be sanctified – both in the sense of being set apart for God, and being set apart from sin. However, when it comes to the Saviour, it cannot mean exactly the same, for there is no need in his case for a process of spiritual cleansing and the removal of the polluting effect of sin.
But how is this separation for God and from sin in the lives of the disciples to take place? How are they – and we – to be made more and more holy and therefore useful to God?
The Means of Sanctification
The answer is, says Jesus, “in the truth” (v17). And just in case we are in any doubt what he means – especially in this confused world which we live in today where everybody and anybody’s definition of truth is acceptable, he clarifies things – “…your word is truth”.
The Scriptures, applied to the hearts of men and women by the working of the Holy Spirit, are the primary agency by which we are separated for God and separated from sin.
See, for example:
John 15:3 – “Already you are clean because of the word that I have spoken to you.”
Ephesians 5:25-26 – “Husbands, love your wives, as Christ loved the church and gave himself up for her, that he might sanctify her, having cleansed her by the washing of water with the word.”
I can’t improve on this explanation by Don Carson
Jesus’ followers will be ‘set apart’ from the world, reserved for God’s service, insofar as they think and live in conformity with the truth, the ‘word’ of revelation (v6) supremely mediated through Christ (himself the truth, 14:6, and the Word incarnate, 1:1, 14) — the revelation now embodied in the pages of this book. In practical terms, no-one can be ‘sanctified’ or set apart for the Lord’s use without learning to think God’s thoughts after him, without learning to live in conformity with the ‘word’ he has graciously given. By contrast, the heart of ‘worldliness’, of what makes the world the world (1:9), is fundamental suppression or denial of the truth, profound rejection of God’s gracious ‘word’, his self-disclosure in Christ.[1]
[1] Carson, D. A. (1991). The Gospel according to John (pp. 565–566). Inter-Varsity Press; W.B. Eerdmans.