When Jesus was praying, the images of Moses and Elijah, which we regard as ghosts appeared, and they had conversations with Jesus. My question is, although the Bible says there should be no relationship between the living and the dead, why did Jesus Himself, who is the author and finisher of our faith, do it?
Let’s read Matthew 17:1-4, 9: “Now after six days Jesus took Peter, James, and John his brother, led them up on a high mountain by themselves; and He was transfigured before them. His face shone like the sun, and His clothes became as white as the light. And behold, Moses and Elijah, APPEARED TO THEM, TALKING WITH THEM. Then Peter answered and said to Jesus, ‘Lord, it is good for us to be here; if You wish, let us make here three tabernacles; one for You, one for Moses, and one for Elijah’….Now as they came down from the mountain, Jesus commanded them, saying, ‘Tell the VISION to no one until the Son of Man is risen from the dead.’”
In your question you assume that Moses and Elijah were GHOSTS; that is, they were SPIRITS which appeared and thus Peter, James and John did not see them in “physical bodies” but in a “spiritual form.” Others have suggested the same thing, and they believe this because Jesus told them “Tell the VISION to no one.” A “vision” can indeed be, as one has said, “a supernatural picture seen in the mind or eyes” and not a material reality.
Others believe that Elijah and Moses appeared to them in “physical bodies” which could be seen with their physical eyes. Lukes’s account of this scene could support this view for we read in Luke 9:28-32 “Now it came to pass, about eight days after these sayings, that He took Peter, John, and James and went up on the mountain to pray. As He prayed, the appearance of His face was altered, and His robe became white and glistening. And behold, TWO MEN talked with Him, who were ELIJAH AND MOSES, who appeared in glory and spoke of His decease which He was about to accomplish at Jerusalem. But Peter and those with him were heavy with sleep; and WHEN THEY WERE FULLY AWAKE, THEY SAW HIS GLORY AND THE TWO MEN WHO STOOD WITH HIM.” In this view Peter, James, and John were not in a trance having a “spiritual vision”; they were FULLY AWAKE and saw the Lord Jesus transfigured and TWO MEN with him who were talking with him. In other words, this vision was a “physical reality.”
I will not take a dogmatic stand on which view is correct. What should impress us is the fact that God allowed these three men to see and hear Moses and Elijah. How did they recognize them? They didn’t have pictures of them in that day for there was no such thing as a camera. Did they recognize them from the Old Testament descriptions of them? For example, perhaps Moses had a ROD in his hand as seen in Exodus 4:1-5, 17 and Elijah was wearing a LEATHER GIRDLE as seen in 2 Kings 1:8. Or did they possess INTUITIVE KNOWLEDGE because the Lord was giving a foretaste of the coming glory? We simply don’t know and it is better to be safe and avoid being dogmatic.
This “foretaste of the coming glory” should be our focus in this marvelous scene. It was a “preview of the coming kingdom” when the Lord Jesus will then be glorified as “King of kings, and Lord of lords” (Revelation 19:11-16). Moses and Elijah represent all those who will have been raptured to heaven (Moses picturing those who had died and Elijah those who were alive when Christ translates them to glory) and who will return with Him when He sets up His kingdom. And Peter, James, and John foreshadow the faithful Jewish remnant who, having survived the coming Tribulation Period, will be alive on earth at His appearing.
Regarding Jesus having a conversation with Moses and Elijah, I would point you to Luke 20:37-38 which reads, “But even Moses showed in the burning bush passage that the dead are raised, when he called the Lord ‘the God of Abraham, the God of Isaac, and the God of Jacob.’ For He is not the God of the dead but of the living, for all live to Him.” This means that when believers DIE, they are still ALIVE. Though their bodies may be in a grave, their souls and spirits LIVE on in the Lord’s presence. Jesus does NOT seek to “contact the dead;” He has to do with “the living.” On the mount Jesus was literally speaking with Moses and Elijah (LIVING believers), whether they were in a “spiritual form” and a “physical form.” (DO) (676.5)