... we are being disciplined so that we will not be finally condemned with the world. (1 Cor. 11:32)
If you belonged to the world, it would love you as its own. As it is, you do not belong to the world, but I have chosen you out of the world. That is why the world hates you. (John 15:19)
Do not be conformed to this world, but be transformed by the renewal of your mind (Rom. 12:2)
Do not love the world or anything in the world. If anyone loves the world, love for the Father is not in him. For everything in the world—the lust of the flesh, the lust of the eyes, and the pride of life—comes not from the Father but from the world. The world and its desires pass away, but whoever does the will of God lives forever. (1 John 2:15-17)
We long for that which is beyond the world, and we think the world itself can fulfill that longing.
But the life that is outside the world is also in the world, indeed is in us. As we cultivate it, it grows - of its own accord, we know not how. (Mark 4:27) But it is not of the world, even if it is in the world. It will live forever, even as the world around it passes away.
We Christians know so little of this. Even the best of us continue to seek after worldly things. But in one way or another the world will always let us down.