RC Sproul, Jr. writes:
"If you are alive and not on the moon, you have successfully managed to be "in the world." Now let's work on not being of the world."
I must quibble with this. He asserts we need do no work to be in the world. But it does take work to learn one's cultural assumptions and happenings to know how to speak to them most effectively.
It's true we need to work harder on our holiness. But we need to engage a lost world just as deliberately.