This episode of the Transfiguration of the Lord has inspired many theologians, preachers, and icon painters. The fact that Christ revealed His glory to the disciples is a very important moment in the relationship between God and people. God once again confirms what He said through the prophet Amos, that He does nothing without revealing His secret to people. In this miracle Jesus allows the disciples to see His face transfigured by eternal glory, so that afterward they would have the possibility of recognizing Him in the Resurrection. It is not His fault that the disciples fell on their faces. And the appearance of Elijah and Moses speaking with Christ allowed the disciples to understand better Jesus' words: "To God all are alive" (cf. Luke 20:38).
In addition, here God repeats His testimony about the Son, the perfect Son of the perfect Father. The perfection of fatherhood is in the Father's love for the Son. The perfection of sonship is in the Son's obedience to the good will of the Father. Therefore all the Father's favor is revealed in the Son; in His life God's will for all of us is disclosed, and from this follows: "Listen to Him"