How are pastors progressively reforming?

Jeff Pollard explains in this video that when he listens to older sermons that he has preached, he realizes that he has made multiple errors in his preaching. He acknowledges that there is always going to be reformation no matter how old you are. While he realizes that he has matured and reformed from where he used to be, there still is much room for continued improvement.  

We continue to be reformed as we are transformed by the grace of God and living day by day according to His Word. 

Romans 12:2 (NKJV) - "And do not be conformed to this world, but be transformed by the renewing of your mind, that you may prove what is that good and acceptable and perfect will of God."

When I have heard older messages that I've done, especially those from a couple of decades ago, I blush with shame. It's one of the, my life was a commentary on why you don't give a novice the pulpit. And I can hear things and theological errors that I should never have attempted to say. And as I look at my life now, I know I haven't arrived. I know that I'm not what I used to be.

I'm thankful to God for His grace, for what he has let me come to be thus far, but there is far more to go. So there's always going to be reform, always going to be those changes in our lives, and it all comes from being transformed by the regenerating grace of the Holy Spirit being brought into union with the Lord Jesus Christ and living day by day according to the light of his word. You