There is a certain book out there now that proposes to tell you how you can become better than who you are today. It sounds like a nice and desireable thing, and it's even written by a pastor of an extremely large church. However, I'm not so sure that these verses could be found within the books pages.
Ephesians 4:17-24 (ESV)
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.
Paul says that this is the way to becoming a better you: put to death the old self, and become like Christ.