The words "In the world but not of the world" never appear in the Bible, but their meaning is clearly implied in Jesus' High Priestly Prayer, John 17:15-16: "I pray not that thou shouldest take them out of the world, but that thou shouldest keep them from the evil. They are not of the world, even as I am not of the world."
Jesus said we would remain in the world, but are not of the world even as he is not of the world.
After wrestling with my faith through adolescence and early adulthood, one of my favorite Scripture passages has come to be Jeremiah 6:16: "Thus saith the LORD, 'Stand ye in the ways, and see, and ask for the old paths, where is the good way, and walk therein, and ye shall find rest for your souls . . ."
The right way has existed for a long, long, time. And the wrong way has existed for almost as long, ever since humanity realized that God had given people a choice about following in the old paths or not.
In the Church debate over new technology (which has been ongoing since the birth of the Church), I find it easiest to ask this question: Is this [fill in the new technology here] good for disseminating the Gospel of Jesus Christ, and does it keep us on the old paths or get us into the thicket? There is nothing wrong with technology. The Protestant Reformation was fueled by Gutenberg's movable-type printing press. A quick search of the Internet will reveal searchable Bibles, commentaries, sermons in print, audio, and video, daily blogs, devotions, and general encouragement in the name of Jesus Christ.
The question is not whether these new tools are good or evil within themselves; they are neither: they are neutral. The question is whether this tool, that tool, an old tool, or some yet uninvented tool will best help us fulfill Jesus' charge to, "Go ye into all the world, and preach the gospel to every creature."