John 17:17

"To sanctify" (Gr. hagiazo) means to set apart for God’s service (cf. Exodus 28:41; Jeremiah 1:5). Jesus is the perfect example of a sanctified person. He devoted Himself completely and consistently to God’s will for Him. Sanctification in John’s Gospel is always for a mission. [Note: Carson, The Gospel . . ., p. 566.] The means of the disciples’ sanctification was the truth, which Jesus explained was God’s Word. Jesus came to reveal God’s word to humankind (John 1:1; John 1:14; John 14:6), and the Spirit would help His disciples understand it (John 15:13). It is both personal and propositional. It comes to us through the living Word of God, Jesus Christ, and the written Word of God, Scripture.

The way Jesus asked the Father to sanctify the disciples was by using His word. This means that it is essential for disciples to know, understand, believe, and obey the revelation that God has given us. The words of God that Jesus revealed and that stand recorded in the Bible are the key to believers’ practical sanctification. Practical sanctification involves separation unto God from the world, the evil one who controls it, and the lies that He promotes that the world believes.

"With the mind, we learn God’s truth through the Word. With the heart, we love God’s truth, His Son [cf. John 14:6]. With the will, we yield to the Spirit [of truth, cf. John 14:17; John 16:13] and live God’s truth day by day. It takes all three for a balanced experience of sanctification." [Note: Wiersbe, 1:370.]