King David says, to the pure God shows Himself pure (Psalm 18:26).
C.S. Lewis in Mere Christianity says that when we dislike qualities in others, it’s because we ourselves have those same qualities. But we’re not even aware we have them.
My older brother used to say people are mirrors to you. If you need to discuss something, the others can tell you an answer you didn’t see before.
2 Corinthians 3:18, “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.”