The Sin of Worldliness: you can't love the world and be a biblical Christian

'Worldliness: it involves love for earthly things, esteem for earthly values, and preoccupation with earthly cares. Scripture plainly labels it sin - and sin of the worst stripe. It is a spiritual form of adultery that sets one against God Himself.'

~ John MacArthur

'Do not love the world or the things in the world. If anyone loves the world, the love of the Father is not in him. For all that is in the world—the desires of the flesh and the desires of the eyes and pride in possessions—is not from the Father but is from the world. And the world is passing away along with its desires, but whoever does the will of God abides forever.'~ 1 John 2:15-17

Jas 4:4  You adulterous people! Do you not know that friendship with the world is enmity with God? Therefore whoever wishes to be a friend of the world makes himself an enemy of God. 

Col 2:8  See to it that no one takes you captive by philosophy and empty deceit, according to human tradition, according to the elemental spirits of the world, and not according to Christ.