A friend shared her candy with me recently. It was something I hadn't tasted since I was a child. After quickly popping the treat in my mouth, I realized that although this was a childhood favorite, it didn't carry over into adulthood. Bleh.
Just as our palate matures, our faith should do the same. Brand-new Christians don't have the same development as 30-year believers. We all need to be making slow and steady progress forward, though.
It is natural to fight against big, glaring sins that are evident to all. They are hard work to leave behind, but well worth the battle. Only after this is accomplished, will it be time to really do some deep cleaning in our souls; that internal struggle you face with your own shortcomings and failures. Before, these things didn't bother the mind, but now they seem to glare in your face. Too long, they've maintained their place on the shelf of "pet sins."
We can mature spiritually through study of God's Word, time spent in prayer and praise, worshipping at church and energetic conversations about faith with both believers and non-believers.
God has a best plan for us, and knows what we can achieve in our lives--through Him. When we get in our Father's way, and push our own agenda before His, we end up with something not quite as good.
Let God do the polishing.
Be not angry that you cannot make others as you wish them to be, since you cannot make yourself as you wish to be. ~Thomas à Kempis, Imitation of Christ, c.1420