The appearance of Moses and Elijah during the Transfiguration was to

The appearance of Moses and Elijah during the Transfiguration was to confirm their legal and prophetic roles. They represented the Law and the Prophets of the Old Testament, respectively. Their appearance was a sign that Jesus was the fulfillment of these scriptures and that he was the long-awaited Messiah. This event was also a way for God to show his approval of Jesus and to prepare him for his upcoming crucifixion and resurrection. It was not to congratulate Jesus on the success of his ministry or to assure him of victory over his enemies, nor was it for Moses and Elijah to settle down with Jesus in glory.