(See source below)
The Bible defines worldliness by centering morality where we intuitively know it should be. Worldliness is the lust of the flesh (a passion for sensual satisfaction), the lust of the eyes (an inordinate desire for the finer things of life), and the pride of life (self-satisfaction in who we are, what we have, and what we have done). Worldliness, then, is a preoccupation with ease and affluence. It elevates creature comfort to the point of idolatry; large salaries and comfortable life-styles become necessities of life.
Worldliness is reading magazines about people who live hedonistic lives and spend too much money on themselves and wanting to be like them. But more importantly, worldliness is simply pride and selfishness in disguises. It’s being resentful when someone snubs us or patronizes us or shows off. It means smarting under every slight, challenging every word spoken against us, cringing when another is preferred before us. Worldliness is harboring grudges, nursing grievance, and wallowing in self-pity. These are the ways in which we are most like the world.
Dave Roper, The Strength of a Man, quoted in Family Survival in the American Jungle, Steve Farrar, 1991, Multnomah Press, p. 68.