I like this word. You may know the English form of it as metamorphosis and think of caterpillars becoming butterflies. Metamorphoō is a compound word formed from meta (G3326) and metaschematizo (G3345). Meta is translated as “with or among us” most of the time; metaschematizo means to “transform”. 

There are three forms of metamorphoō in the New Testament. Matthew 17:2 and Mark 9:2 use this word to describe Jesus’ change on the mountain when He speaks to Moses and Elijah. In Romans 12:2 it is used to describe our mind being changed to know the will of God. 2 Corinthians 3:18 describes our change as we look at ourselves and realize how we are looking and acting more like Jesus all the time.

The first time we see this type of change is in Moses when he received the stone tablets and went into the presence of God to talk with Him. This glorious change faded, and he had a veil to hide it from the people. (Exodus 34:29-35 and 2 Corinthians 3:7-18)  

Jesus was among us when He transformed on the mountaintop. This glory also faded, but I think He was still glowing when He was among the crowd and healed the boy. For sure the demon saw something.

Jesus was transformed again when He came out of the tomb as the true form of Himself. This God-Man (Christ Jesus) is who we are becoming as we change our thinking and acting to be the righteous people of God. I am thankful for the Father’s grace in this process, I could not do it without Him.

μεταμορφόω | Free Online Greek Dictionary | billmounce.com

G3339 – metamorphoō – Strong’s Greek Lexicon (kjv) (blueletterbible.org)