There were no others who could better encourage Jesus in His impending trial and death than those who had previously been His representatives on earth and who had suffered at the hands of those whom they had tried to lead.
“At the transfiguration the Lord sent Moses and Elijah to talk with Jesus concerning His sufferings and death. Instead of choosing angels to converse with His Son, God chose those who had themselves experienced the trials of earth.” Early Writings, 162.
“The Father chose Moses and Elijah to be His messengers to Christ, and glorify Him with the light of Heaven, and commune with Him concerning His coming agony, because they had lived upon earth as men; they had experienced human sorrow and suffering, and could sympathize with the trial of Jesus, in His earthly life. Elijah, in his position as a prophet to Israel, had represented Christ, and his work had been, in a degree, similar to that of the Saviour. And Moses, as the leader of Israel, had stood in the place of Christ, communing with Him and following His directions; therefore, these two, of all the hosts that gathered around the throne of God, were fittest to minister to the Son of God.” The Spirit of Prophecy, vol. 2, 329.
“Elijah had walked with God. His work had been painful and trying, for the Lord through him had reproved the sins of Israel. Elijah was a prophet of God; yet he was compelled to flee from place to place to save his life. His own nation hunted him like a wild beast that they might destroy him. But God translated Elijah. Angels bore him in glory and triumph to heaven.
“Moses was greater than any who had lived before him. He had been highly honored of God, being privileged to talk with the Lord face to face, as a man speaks with a friend. He was permitted to see the bright light and excellent glory that enshrouded the Father. The Lord through Moses delivered the children of Israel from Egyptian bondage. Moses was a mediator for his people, often standing between them and the wrath of God. When the anger of the Lord was greatly kindled against Israel for their unbelief, their murmurings, and their grievous sins, Moses’ love for them was tested. God proposed to destroy them and to make of him a mighty nation. Moses showed his love for Israel by his earnest pleading in their behalf. In his distress he prayed God to turn from His fierce anger and forgive Israel, or blot his name out of His book.” Early Writings, 162, 163.
Also we are told that “Moses was present to represent those who will be raised from the dead at the second appearing of Jesus. And Elijah, who was translated without seeing death, represented those who will be changed to immortality at Christ’s second coming and will be translated to heaven without seeing death.” Ibid., 164.