Our own way of thinking and living, outside of Christ, leads to death and destruction. And as we’ve probably all found, the tide of the world can pull us out to the waves of our own fearful whims, temporary idols, and limited conclusions.
This is why Paul calls us to renew our minds, becoming like Christ. In this passage, he calls us to consume less of what the limited world has to offer and more of what the unlimited God has to fulfill us. Through this, He crafts us into renewed men and women, brimming with life.
Now this I say and testify in the Lord, that you must no longer walk as the Gentiles do, in the futility of their minds. They are darkened in their understanding, alienated from the life of God because of the ignorance that is in them, due to their hardness of heart. They have become callous and have given themselves up to sensuality, greedy to practice every kind of impurity. But that is not the way you learned Christ!—assuming that you have heard about him and were taught in him, as the truth is in Jesus, to put off your old self, which belongs to your former manner of life and is corrupt through deceitful desires, and to be renewed in the spirit of your minds, and to put on the new self, created after the likeness of God in true righteousness and holiness.