John 17:17 English Standard Version (ESV)
17 Sanctify them[a] in the truth; your word is truth.
Footnotes: a Greek Set them apart (for holy service to God)
Vines Expository Encyclopedia for the Greek word rendered sanctify is; the separation of the believer from the world in his behavior — by the Father through the Word.
The footnote is a reflective reaction to encourage readers to go a step beyond the definition and remind them they are servants of God. While this is true, it appears to be a distraction from the truth which is the vehicle of delivery of sanctification. I say vehicle because you have to get in a vehicle in order for it to take you anywhere.
Jesus is the Truth, Jesus is the Word made flesh. We know this from John’s gospel, chapter 1.
John 14:20 English Standard Version (ESV) In that day you will know that I am in my Father, and you in me, and I in you.
I seems easier to see Christ in us than it does us being in Christ. How we feel about ourselves hinders that vision because we know deep down we are sinners and He is holy. We would defile Him to our minds thinking. God has sanctified us unto Himself. His Word is truth, even if we don’t see it exactly as He does.
On the brighter side of John 17:17 having the Word reside in us changes us from the inside out. Change is relative to position and being in Christ those changes are because He performs them. A changed heart will insist on right actions and behaviors change.
Read God’s Word, which is in you, confirming what is true and the mind we begin to see the truth and align itself with the condition of the new heart.
Ezekiel 36:26 English Standard Version (ESV) And I will give you a new heart, and a new spirit I will put within you. And I will remove the heart of stone from your flesh and give you a heart of flesh.