Answer
In John 15:3, Jesus says to His disciples, “You are already clean because of the word which I have spoken to you” (NKJV). To grasp the profundity of this statement, it is necessary to review the context of John 15 and related passages.
In the preceding verses of John 15, Jesus employs a metaphor of the vine and the branches. The Father is the vinedresser; the Son is the “true vine” (John 15:1). Believers are the branches (verse 5). To ensure maximum fruit production, the Father does two things: 1) He removes unfruitful branches, and 2) He prunes fruitful branches (verse 2; cf. Hebrews 6:7–8).
The word prune means “to cut back or trim.” In horticulture, pruning is a necessary practice in which dead or overgrown branches are removed from a plant to promote growth and fruitfulness. Figuratively, the Father prunes believers to shape them into the image of his Son: “The Lord disciplines the one he loves, and he chastens everyone he accepts as his son” (Hebrews 12:6; cf. Deuteronomy 8:5).
The idea is that the Father, as the vinedresser, lovingly prunes or disciplines those who are already bearing fruit—not for punishment, but to increase fruit production. The disciples are “already clean because of the word” (John 15:3). In this context, that means they were “in a condition fit to bear fruit” (The Expositor’s Greek Testament, Nicoll, W. Robertson).
Here, it is helpful to compare John 13:10 and John 15:3. Earlier, Jesus had washed the disciples’ feet, signifying the washing away of sins. Peter, initially resistant, is told by Jesus, “Those who have had a bath need only to wash their feet; their whole body is clean. And you are clean, though not every one of you.” At that point Judas Iscariot is still with the group, and that is why not all of the disciples were “clean.”
In John 15:3, Jesus speaks again of the disciples’ being “clean,” this time in the context of abiding in the True Vine. At this point, Judas has departed, and Jesus can declare to the rest that “you are already clean.”
The disciples’ cleanness comes through the word spoken by Jesus, underscoring the transformative power of God’s Word. The Word of God sanctifies (John 17:17). The eleven disciples, having been changed by Jesus’ teachings, commands, and promises, are prepared for the next step in their spiritual walk—to bear much fruit.
The concept of cleansing through the Word is found throughout Scripture. In Ephesians 5:26–27, for instance, the apostle Paul writes that Christ has cleansed the church “by the washing of water with the word, so that he might present the church to himself in splendor, without spot or wrinkle or any such thing, that she might be holy and without blemish” (ESV).
In Psalm 119:9, the psalmist draws a connection between cleansing and obedience to the Word of God: “How can a young man cleanse his way? By taking heed according to Your word” (NKJV).
The writer of Hebrews says that “the word of God is alive and active. Sharper than any double-edged sword, it penetrates even to dividing soul and spirit, joints and marrow; it judges the thoughts and attitudes of the heart” (Hebrews 4:12). How we need the Word to keep our thoughts true, honorable, just, pure, lovely, commendable, excellent, and worthy of praise (Philippians 4:8)!
As we meditate on John 15:3, we are reminded of the Father’s pruning technique, the Son’s transformative Word, and the need to bear much fruit (verse 5). In Christ, we can do all things (Philippians 4:13), but apart from Him we can do nothing (John 15:5).
