So many times I think in such black and white terms, especially when it comes to holiness and worldliness. There are so many passages that encourage us to flee the world, like "Do not love the world nor the things in the world. If anyone loves the world, the love of the Father is not in him." 1 John 2:15 or in James 4:4 "You adulteresses, do you not know that friendship with the world is hostility toward God? Therefore whoever wishes to be a friend of the world makes himself an enemy of God."
James uses very strong language to motivate us as Christians to flee worldliness, that is if we're perceptive. It's important to define what the word "world" means at this point, is it that we listen to secular music or we have a beer with our dinner once in a while? are we worldly if we drive a new car? These things are things of this world and have a potential to make us worldly, but these activities and things are not necessarily signs of worldliness.
As WM P. Farley says in his book Outrageous Mercy, "Worldliness is too subtle to be analyzed this simply. Worldly people are those who have internalized the values of the fallen world around them."
Worldliness is best defined as independence from God, it's a central feature of worldliness. When we think about worldliness we think of people who are irreligious like Marilyn Manson or any big named celebrity. Again in Outrageous Mercy, Farley gives a great example, "the Titanic is really a better model of worldliness, because the spirit of the Titanic energizes worldly behavior."
The false confidence that deceived the passengers of the Titanic is similar to the false sense of confidence and hope that the world offers us as believers, a spiritual titanic.
The spirit of the world says that "I'm good, I don't really need Christ or his cross." It's proud independence not drinking and not listening to secular music is the real heart and soul of worldliness because if we don't do those things, we think that we're good and tend to look down on others who don't act as good as we do.
The things of this world will never satisfy us, only in feasting on Jesus and looking to the cross will true satisfaction and true happiness occur.