After six days Jesus took Peter, James, and John and led them up a high mountain apart by themselves. And he was transfigured before them, and his clothes became dazzling white, such as no fuller on earth could bleach them. Then Elijah appeared to them along with Moses, and they were conversing with Jesus. Then Peter said to Jesus in reply, “Rabbi, it is good that we are here! Let us make three tents: one for you, one for Moses, and one for Elijah.” He hardly knew what to say, they were so terrified. Then a cloud came, casting a shadow over them; then from the cloud came a voice, “This is my beloved Son. Listen to him.” Suddenly, looking around, they no longer saw anyone but Jesus alone with them. As they were coming down from the mountain, he charged them not to relate what they had seen to anyone, except when the Son of Man had risen from the dead. So they kept the matter to themselves, questioning what rising from the dead meant. Then they asked him, “Why do the scribes say that Elijah must come first?” He told them, “Elijah will indeed come first and restore all things, yet how is it written regarding the Son of Man that he must suffer greatly and be treated with contempt? But I tell you that Elijah has come and they did to him whatever they pleased, as it is written of him.” (Mk 9:2-13)
The disciples together, in the person of Peter, accepted Jesus as the Messiah. The disciples understood who Jesus was. When the disciples were challenged with the life and mission of Jesus again they did not understand Jesus. Transfiguration is another point of explanation for the disciples. Through this Jesus makes the disciples to understand his mission. But gain they are with lack of understanding with regard to the rising from the dead.
The disciples are through a process of formation. The process is leading them from a lack of understanding to understanding. The process takes them first regarding the kingdom who Jesus is with regard to the kingdom then he makes them understand his mission and them from here he has to proceed to resurrection. His preaching, doing miracles, transfiguration etc are the means by which he leads them through formation.
This formation process is for the disciples only. First when Peter said that Jesus was the messiah, he asked the disciples not to tell anyone regarding this. Now again after transfiguration Jesus does the same thing. (he charged them not to relate what they had seen to anyone, except when the Son of Man had risen from the dead). Formation cannot be for a big group. It should personal or to a very small group.
