Those who follow Christ are, like him, not of the world. For this reason the world may hate us. So we should ask God to keep us from the evil one and sanctify us in his truth.
Perhaps you’ve heard that Christians are (or ought to be) in the world but not of the world. You’ve learned that those who follow Jesus should interact with their friends and neighbors (the world) but they should also be distinct, with different priorities and standards.
This phrase is common in Christian circles, but many may not know where it comes from. Is this a biblical saying? If so, are we using it correctly? If we read the Bible as a whole and not as an inspirational-motto jukebox, we’ll see that some familiar expressions take on a deeper meaning than we originally thought.
Within the Gospel of John
Let’s dispense with one thing first. “In the world but not of the world” does not appear in the Bible. Rather, it is a simple phrase that joins two sayings of Jesus together in a memorable way.
We find the pieces of this phrase in Jesus’s “high priestly prayer” in John 17. Jesus prays this prayer at the end of his last meal with his disciples, after Judas leaves to betray him (John 13). Jesus addresses the remaining disciples for three chapters (John 14–16) regarding his departure and the coming of the Holy Spirit. At the beginning of John 17, Jesus turns from talking to the disciples to praying to his Father for those same disciples.
In the World
My hunch is that “in the world” was pulled from John 17:11.
And I am no longer in the world, but they are in the world, and I am coming to you. Holy Father, keep them in your name, which you have given me, that they may be one, even as we are one. (John 17:11)
Jesus was thinking about his departure from earth, contrasting where he will be (“no longer in the world”) with where the disciples will be (“in the world”). By “in the world,” Jesus means that the disciples are walking around on the earth like other living humans. This conclusion follows from the beginning of Jesus’s prayer.
I glorified you on earth, having accomplished the work that you gave me to do. And now, Father, glorify me in your own presence with the glory that I had with you before the world existed. (John 17:4–5)