John 17:16
John 17:1616They are not of the world, just as I am not of the world.
This is the flagship verse for JW separation theology. The Watchtower applies "they are no part of the world" to political neutrality (no voting, no military service, no flag salute), social neutrality (no sports teams, no clubs, no civic associations), career neutrality (no armed work, no high political office), and relational neutrality (no close friendships outside the organisation). The verse is treated as the structural justification for the entire withdrawal programme.
Jesus' statement is conditional on the verse immediately before it. In v.15 he has just prayed that the Father NOT take the disciples out of the world. The "no part of the world" of v.16 therefore cannot mean withdrawal — Jesus has ruled that reading out one verse earlier. What "no part of" means is moral and spiritual non-belonging: the disciples' identity, allegiance, and hope are not in the world's value system, even while they live, work, and witness inside it. The same Greek phrase (ek tou kosmou ouk eisin) describes Jesus himself — and Jesus was eating with tax collectors and sinners while not being "of" the world. Membership in Christ's kingdom is what makes the Christian "no part of" the world; geographic and relational separation is not the mechanism.
The NWT renders ek tou kosmou ouk eisin as "they are no part of the world" — a periphrastic expansion of the literal "are not of the world." Standard translations read "they are not of the world" (ESV, NIV, NASB, KJV). The "no part of" wording is a JW-distinctive phrasing that hardens the genitive of source ("of, from") into a stronger separation register ("no part of"). The slogan reads as a membership-category statement rather than the value-orientation statement Jesus prayed — and feeds directly into the Watchtower's categorical withdrawal doctrines.