Reading from the Book of II Corinthians 3:18, 4:16
II Corinthians 3:18 And we all, who with unveiled faces contemplate the Lord’s glory, are being transformed into his image with ever-increasing glory, which comes from the Lord, who is the Spirit.
We change gradually, little by little, or as II Corinthians states, "from one degree of glory to another." While these changes take place, we still make mistakes, and God's forgiveness is always available to us through Jesus Christ. Receiving this forgiveness actually strengths us and enables us to keep pressing on toward new levels of holiness and better inner beings.
II Corinthians 4:16 Therefore we do not lose heart. Though outwardly we are wasting away, yet inwardly we are being renewed day by day.
Mirrors don't reflect the inner part of us that lasts forever. And when trials knock on our doors, looking cool won't prepare us to victoriously meet their test. The apostle Paul describes the inner man as being renewed day by day as spiritual muscles grow stronger. He wasn't a perfect specimen of health, but Paul survived persecution and imprisonment because he lived his life from the inside out, focusing on eternity.
What's at the core of your life? Are you so focused on looking in the mirror at your outer self that you haven't spent time strengthening your inner person through studying God's Word and praying without ceasing? Try looking at the "inner mirror" of yourself.