We're pretty much suckers for "new", aren't we? New phone, new car, new house, new shoes, new wardrobe, new haircut, new friends, new you... What's not to like about new?
Advertisers have leveraged the power of "new" for decades, using it to sell widgets and whatnots to the willing masses. But maybe the most remarkable phrase in advertising history is this one -- "new and improved". Have an old product that can't outdo the new? Bippity-boppity-new-and-improved!
What's more, government regulations only require a minor functional change to a given product or its packaging to enable brands to slap a "new and improved" label on it. And we buy it!
This is indicative of the pattern of this world. Humankind has an almost infinite capacity to fool ourselves. This is true of our spiritual newness as well. We want to believe we're basically good people and that we (possibly with God's help) only need to make a few simple tweaks and we can show ourselves to the world as new and improved.
Scripture compels us to not be conformed to the pattern of this world. Consider the words of C.S. Lewis in his book Mere Christianity.
"...Mere improvement is not redemption, though redemption always improves people even here and now and will, in the end, improve them to a degree we cannot yet imagine. God became man to turn creatures into sons: not simply to produce better men of the old kind but to produce a new kind of man."
The nature of sin is such that, try as we might, even the best of our improvements won't last. Renewal is reminding yourself of who Jesus is. That He came to transform your very nature by giving you His own! Talk about new and improved.