14 I have given them your word, and the world has hated them because they are not of the world, just as I am not of the world. …16 They are not of the world, just as I am not of the world. 17 Sanctify them in the truth; your word is truth.
John 17:14, 16–17

By the Word we are not of the world (born from above) and by the Word we are not of the world (conformed to the image of the Son).
By the Word we are holy (set apart from the world) and by the Word we are holy (conformed to heaven).
By the Word we are saved and by the Word we are sanctified.
By the Word we are a new creation in Christ and by the Word we become more of what we are.
By the Word we are regenerated and by the Word we are renewed.
It is by the Word that the disciples are not of this world (born from above). Jesus has said he has received authority to give eternal life to all who are given to Him (v. 2). This eternal life is to know the Father and the Son (v. 3). Jesus manifests (makes known) the name of the Father to the people given to Him, the name the Son Himself bears (vv. 6, 11–12). The means by which the Father and Son are known and manifest to them is the Word of God received with faith.
“Now they know that everything that you have given me is from you. For I have given them the words that you gave me, and they have received them and have come to know in truth that I came from you; and they have believed that you sent me.”
—John 17:7–8
In other words, the way by which you come to not be of this world is through the Word that is given to you as the elect of the Father. “[Y]ou have been born again, not of perishable seed but of imperishable, through the living and abiding word of God… And this word is the good news that was preached to you” (1 Peter 1:23, 25). It is because of this that Peter can go on to say, “…They stumble because they disobey the word, as they were destined to do. But you are a chosen race, a royal priesthood, a holy nation, a people for his own possession, that you may proclaim the excellencies of him who called you out of darkness into his marvelous light” (2 Peter 2:8–9). By the Word they are not of this world.
Further, it is by the Word that the disciples are not of this world (sanctified). The saints, set apart in Christ, are made saintly, by the Word. Yes, you may read, study, and memorize Scripture and not be sanctified (i.e the Pharisees), but do not doubt this, you cannot be sanctified unless you read, study, and memorize the Scriptures.
Jesus gives the Word to His people and His people keep His Word (17:6). They keep the Word because they are kept (vv. 11–12, 15). Many who profess to have received the Word for salvation, give little indication that they truly have by their lack of sanctification. The Word is not treasured as it should be. The world is treasured as it should not be. Oh how many are glutted on this world and fast from the Word. The Word is not to be treated like a single use inoculation. It is food.
The Word is the means by which you are kept. If you are not keeping the word, you are in grave danger of falling away. Do not take it for granted that you stand, that you believe, that you will remain faithful. Saints, read, study, meditate, memorize and pray the word. Be earnest to immerse yourself in a church that sings, prays, reads, hears, and preaches the word and sees the word in the sacraments. Saints, this world bombards you with lies. You must gorge on truth.
Saints, if your Lord prays for you to be sanctified by the Word, will you neglect the Word that sanctifies? It is like neglecting breathing for twenty-three hours a day and boasting that you are living because you breathe for one. Too many have thrown one punch and boast as if they are fighting the fight. Too many have taken one step and boast as if they are running the race. Too many have made one profession and boast as though they keep the faith.
The Spirit of Psalm 119 is alien to them and for this reason they are not aliens in this world. They are at home in it. Oh that this Word may sanctify our souls by creating in us this very hunger for the Word that sanctifies.
How can a young man keep his way pure? By guarding it according to your word. With my whole heart I seek you; let me not wander from your commandments! I have stored up your word in my heart, that I might not sin against you. Blessed are you, O LORD; teach me your statutes! With my lips I declare all the rules of your mouth. In the way of your testimonies I delight as much as in all riches. I will meditate on your precepts and fix my eyes on your ways. I will delight in your statutes; I will not forget your word. —Psalm 119:9–16