Luke 9:29 “As He prayed, the appearance of His face was altered, and His robe became white and glistening.”
This is one of many sights in Scripture which we can only use our imagination to envision. However, rest assured that the Holy Spirit is able to give us at least an idea in our hearts of the feeling that Peter, James, and John had on this occasion. Even if we cannot re-create the experience, what any believer has with the Holy Spirit living in them is also very wonderful.
Elsewhere the Scriptures use the word ‘transfigured’ to describe this change. So, we really have no reason to think that Jesus looked like a different person. But, the changes that did occur were such that anyone not knowing the facts of the case might easily assume He was a different person. The revealing of His glory was surely enough that these three disciples never looked at Him quite the same again.
Heavenly Father, thank You for Your glorious Son! We are overwhelmed by His glory, mercy, and grace! We will forever magnify Your power and wisdom in the plan of salvation. You are awesome beyond all reckoning. You are so wonderful! In the Name of the Lord Jesus Christ I pray and praise You, Amen.