The transfigured light that radiated from Jesus has inspired many as an image of our potential for holiness. Some Eastern Orthodox spiritual writers such as Gregory Palamas and St. Seraphim of Sarov believed that they saw the light of Mount Tabor within.
Jesus’ self-designation “the Son of Man” is also rich in possibilities for humanity. Walter Wink famously suggested that the phrase “Son of Man” refers to a newly created humanity in Christ. This fits well with St. Paul’s use of the phrase “New Humanity” in Romans 5. For the likes of the disciples and us entry into the new humanity in Christ is not smooth sailing into transfigured light. The disciples quickly return to arguing about who is the greatest. We all know the anger and other discordant feelings that overtake us quickly every time we sense any hint of the transfigured light in our lives. Even Moses and Elijah were both compromised with violence which they had to overcome in the same way we have to overcome our own violent impulses, petty as they often are.
Jesus’ transfiguration is linked to the journey he is about to make to Jerusalem and we know what happened to him there. Jesus was transfigured, then, because he was willing to die in Jerusalem if that turned out to be necessary for opening the way to a new humanity. Jesus tells his disciples as much when he admonishes them not to tell anyone what they have seen until “the Son of Man has been raised from the dead.” (Mt. 17: 9) At that time, Jesus opened the way for a new humanity that would not require human bonding through the death of one for the sake of the people as Caiaphas would have it, but a new humanity that would join in seeking for even one lost sheep, strenuous and dangerous as such seeking could be, and then rejoicing when that sheep was found. (Lk. 15: 3–7)
That the Transfiguration takes place on a mountain recalls Mount Sinai, where God began the renewal of humanity. The first Commandment that “you shall have no other gods before me” and the last one “you shall not covet” cover our relationships with God and neighbor and create a sandwich with the eight other commandments. More recently there is the Mount where Jesus preached his sermon to renew humanity through non-retaliation and forgiveness, precisely the human qualities Jesus himself showed as the risen forgiving victim. This is the transfigured light that shines in the darkness so that the darkness cannot overcome it. (Jn. 1:3)
See also: How is the Gospel Veiled? and The Transfigured Glory of God’s Children