Jesus had an appointment. The Transfiguration of Christ didn’t just happen as Jesus was walking along with his disciples. He had an appointment on top of that holy mountain to meet with Moses and Elijah, but why?
The week before, at Caesarea Philippi, Peter made the great confession: “You are the Christ, the Son of the living God” (Matthew 16:16). “From that time Jesus began to show his disciples that he must go to Jerusalem and suffer many things from the elders and chief priests and scribes, and be killed, and on the third day be raised” (Matthew 16:21). That made absolutely no sense to them, and Peter rebuked Jesus for saying so (Matthew 16:22)! They needed proof that God was in control. They needed to know that what was about to happen was all part of God’s eternal plan. Let’s read the story of the Transfiguration again:
And after six days, Jesus took with him Peter and James, and John, his brother, and led them up a high mountain by themselves. And he was transfigured before them, and his face shone like the sun, and his clothes became white as light. And behold, there appeared to them Moses and Elijah, talking with him. And Peter said to Jesus, “Lord, it is good that we are here. If you wish, I will make three tents here, one for you and one for Moses and one for Elijah.” He was still speaking when behold, a bright cloud overshadowed them, and a voice from the cloud said, “This is my beloved Son, with whom I am well pleased; listen to him.” When the disciples heard this, they fell on their faces and were terrified. But Jesus came and touched them, saying, “Rise, and have no fear.” And when they lifted their eyes, they saw no one but Jesus only (Matthew 17:1 – 8 ESV).
Have you ever wondered why, out of all the Old Testament characters, Moses and Elijah appeared to Jesus? Why not Adam, the first man? After all, it was because of Adam’s sin that Jesus had to go to the cross. Or why not Abraham? He was the father of the nation of Israel. Or Noah, or Malachi, or even King David? Why these two, and how did Peter, James and John know it was Moses and Elijah?
Remember, Moses was the great lawgiver, and Elijah stood for all the prophets. Thus, the entire Old Testament reflects God’s eternal plan to save us. Peter, James, and John needed to know in the midst of the trial they were about to undergo; God is in control! Isn’t that a great thought for today as well?
 This answers the question I am often asked, “Will we recognize each other in heaven?” Unless Moses and Elijah were wearing name tags, Peter and the others simply knew who it was. So will we when we see the saints.