"Therefore having such a hope, we use great boldness in our speech, and are not like Moses, who used to put a veil over his face so that the sons of Israel would not look intently at the end of what was fading away. But their minds were hardened; for until this very day at the reading of the old covenant the same veil remains unlifted, because it is removed in Christ. But to this day whenever Moses is read, a veil lies over their heart; but whenever a person turns to the Lord, the veil is taken away. Now the Lord is the Spirit, and where the Spirit of the Lord is, there is liberty. But we all, with unveiled face, beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as from the Lord, the Spirit" (2 Corinthians 12-18). (Emphasis mine)
There is no way our physical body can produce anything that is spiritually pleasing to God. It is dead until you put something in it. That something is Jesus Christ and He is what gives it beauty. How do we energize what is inside of us? It isn't something that is automatic or even inevitable. There needs to be the continual renewal of the Holy Spirit. The Spirit of God takes that resurrection life that is in us and begins to transform us.
We need to be beholding something...the glory of God. The glory of God is revealed in the Word of God. It is only when we begin looking at the glory of God through the Word that causes us to be changed. The Word will never lie to us, it will always point us to Christ. Then there is a reflection that radiates back to us. We seek to be like Him. The glory of God is Jesus, all that Jesus Christ is and all that he does. It is only when we look at the glory of God through the glory of Jesus Christ can we be changed.
We also need an unveiled face. We all have to take something off. There isn't a one of us that doesn't cover our "real" face. We don't want people to see our flaws and imperfections. However, we need to make sure we are totally open and honest as we look, as if in a mirror--the mirror of God's Word which is the reflection of Jesus. Unbelief and unresponsiveness of people is a stumbling block because they do not want that much exposure. Do you realize that when you read the Scriptures you are having a one-on-one encounter with the Author? Being less than open with God will hinder our spiritual transformation. Yes, sometimes it hurts when we allow ourselves to go into the presence of God. Allow Him to do all that He desires to do in you. We need to be careful that we are not stagnating in our walk.
There also needs to be an understanding that this transformation is something that He does. We "are being transformed." Sometimes we may not even notice the changes that are taking place in us but other people will. It is a gradual process. As the glory of God radiates to our open heart and mind we are transformed over a lifetime. The issue isn't that we feel it or not, the Spirit of God is working in us. It is God's life, lived out through you as you seek to live out His will.