In a significant passage in John 17, Jesus prays for his disciples, and for all believers:
13 But now I come to You, and these things I speak in the world, that they may have My joy fulfilled in themselves. 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. 15 I do not pray that You should take them out of the world, but that You should keep them from the evil one. 16 They are not of the world, just as I am not of the world. 17 Sanctify[i] them by Your truth. Your word is truth. 18 As You sent Me into the world, I also have sent them into the world. 19 And for their sakes I sanctify Myself, that they also may be sanctified by the truth.
NKJV John 17:13-19 – Jesus Prays for his Disciples
20 “I do not pray for these alone, but also for those who [j]will believe in Me through their word; 21 that they all may be one, as You, Father, are in Me, and I in You; that they also may be one in Us, that the world may believe that You sent Me. 22 And the glory which You gave Me I have given them, that they may be one just as We are one: 23 I in them, and You in Me; that they may be made perfect in one, and that the world may know that You have sent Me, and have loved them as You have loved Me.
NKJV John 17-20-23 Jesus Prays for all Believers
Here Jesus is expressing that God’s word is the ultimate Truth, and it is through God’s Truth that his disciples and all believers are transformed and made holy.
The term “sanctified” means to be set apart or made holy for a special purpose or use. In the context of Christianity, it refers to the process of being made holy through the work of the Holy Spirit, and through the power of Jesus’ sacrificial death and resurrection. This process involves a transformation of one’s character and behavior to conform to God’s will and purposes, and to reflect His nature and attributes. Christians believe that sanctification is an ongoing process that continues throughout a person’s life, as they seek to grow in their relationship with God and become more like Jesus.