Worlidness in the Christian perspective is essentially what is morally defiant of God and his truth. Defined by David Wells in his book "Losing Our Virtue", worldliness is a system of values that, in any given age, has at its center the 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. (https://www.thegospelcoalition.org/blogs/justin-taylor/what-is-wordliness/)