What does Luke 9:30 mean?

Jesus has brought Peter, James, and John to the top of a mountain. Jesus is praying; the other three are asleep (Luke 9:32). As Jesus glows with glory, Moses and Elijah appear to talk about His coming departure from earthly ministry (Luke 9:28–29, 31). There are several theories as to why these two specific men come to speak with Jesus.

The most common theory is that Moses represents "the Law" and Elijah "the prophets," encompassing all Jewish Scripture and the history of God's people (Matthew 5:17; Luke 16:16). Another is that, more generally, they are thought of as the most prominent prophets of the Old Testament. At least for Moses, this is an easy case to make. The entire experience seems to validate Moses' appearance. They are speaking of Jesus' "departure," written in Greek as exodos. Jesus' face shines like Moses' did when He spoke with God on Mount Sinai (Matthew 17:2; Exodus 34:29). Like Moses, Jesus is gathering His people into a cohesive group to worship God. And, most importantly, Jesus is the prophet Moses promised (Deuteronomy 18:15).

Elijah, however, was not necessarily revered as much as other prophets, such as Samuel. Yet because Elijah was taken alive to heaven (2 Kings 2:9–12), he was expected to return. In fact Malachi prophesied, "Behold, I will send you Elijah the prophet before the great and awesome day of the Lᴏʀᴅ comes" (Malachi 4:5). Malachi spoke of a messenger that would herald the Messiah (Malachi 3:1), seemingly linked to Elijah. In a way, John the Baptist fulfilled that prophecy (Matthew 11:7–14), but here Elijah does it personally. Elijah's appearance at the transfiguration might have also been meant to counter the common notion that Jesus was a returned Elijah (Luke 9:8, 19).

In addition, Jesus' ministry does represent Elijah's. Neither had the support of a political leader, as Samuel and Isaiah did. Both vigorously cleaned the land of idolatry (1 Kings 18:20–40; Luke 19:45–46). Both sought God's comfort on solitary mountains (1 Kings 19; Mark 6:46). And both used miracles to meet the needs of people (1 Kings 17:8–24; Luke 7:11–17; 9:10–17). Still, those are relatively shallow parallels.

Moses and Elijah's presence on the mountaintop, in addition to the description of the two witnesses' ministry, have suggested to some that they will be the two witnesses during the tribulation (Revelation 11:1–13). Some go as far as to say that because we do not know where Moses was buried and no one saw him die, he did not die but was taken up to heaven like Elijah, a claim contradicted by Scripture (Deuteronomy 34). Others say the two witnesses will be Elijah and Enoch (Genesis 5:24) because both were taken to heaven without dying. Still others say the witnesses will not be the return of anyone, but rather two currently unknown believers. In truth, we do not know who the two witnesses will be.

The idea that the spirits of loved ones who have died can visit us is common. The Bible doesn't support this belief. Elijah never died, so far as Scripture tells us. Moses, however, died, yet appears during the transfiguration with Jesus. This is one of only two cases in the Bible where the dead return to earth to speak with someone. The first instance was when King Saul visited a medium and asked her to bring back Samuel. God sent Samuel, much to the witch's surprise, but Samuel wasn't happy about it (1 Samuel 28:8–15).