In his book Losing Our Virtue David Wells described worldliness as
that system of values, in any given age, which has at its center our fallen human perspective, which displaces God and his truth from the world, and which makes sin look normal and righteousness seem strange. It thus gives great plausibility to what is morally wrong and, for that reason, makes what is wrong seem normal. (p. 4)
In an interview he elaborated on worldliness in connection with fundamentalism (of yesterday) and evangelicalism (of today):
We have just come out of a period within the evangelical world where worldliness was treated as a very trivial matter. I actually remember the time (this dates me significantly) when Mrs. Billy Graham came to England at the very beginning of Graham’s crusades, and the newspapers carried all kinds of articles about the fact that she was a Christian woman and she wore makeup. There were many Christian women in England, in those olden days, who did not wear makeup — they thought it was worldly.
But it wasn’t only makeup. There was a time when Christians didn’t go to most movies. There were all kinds of worldly things that, within fundamentalism in particular, people didn’t do.
The problem with this was that they identified really quite trivial things as worldly.
If you look in the New Testament, worldliness is not trivial at all. What you have, in fact, is a competing loyalty: anybody who loves the world cannot be a friend of God. That is how profound is the choice that we are making.
So the question is, where and in what ways have these antithetical, competing loyalties intruded into our souls unwittingly?