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 by the Spirit of the Lord. II Cor. 3:18
Good mirrors do not lie.
People who want to know the truth about themselves use mirrors that are as good as possible.
Godly, honest people are good mirrors.
A friend who will reveal your weaknesses to you in private is a good mirror.
The Scriptures honestly read and free of human distortions is a perfect mirror.
The best mirror of all is Jesus. God has chosen Jesus as His perfect mirror that will judge humanity. Eventually every human being will look into Jesus and see their final truth.
Jesus will be the final judge of what human perfection is and He is the only person to whom we can look to become what we must become. Only Jesus can change us into the kind of human beings God has intended for us to be from the beginning. Jesus is the final mirror.