2 Corinthians 3:17-4:1

Now the Lord is the Spirit, and where the Spirit of the Lord is, there is freedom. And all of us, with unveiled faces, seeing the glory of the Lord as though reflected in a mirror, are being transformed into the same image from one degree of glory to another; for this comes from the Lord, the Spirit.

Therefore, since it is by God’s mercy that we are engaged in this ministry, we do not lose heart.