Elijah was taken alive to Heaven in a chariot of fire “And it came to pass, as they still went on, and talked, that, behold, there appeared a chariot of fire, and horses of fire, and parted them both asunder; and Elijah went up by a whirlwind into heaven” (2 kings 2:11).
Moses received a private resurrection by Jesus (Michael) “Yet Michael the archangel, when contending with the devil he disputed about the body of Moses, durst not bring against him a railing accusation, but said, The Lord rebuke thee” (Jude 9).
At the transfiguration, Peter, John, and James were given a preview of the second coming of Christ in His power and glory (Luke 9:28–32). Elijah appeared as a representative of the saints who will be translated without seeing death when Jesus comes, and Moses as a representative of the righteous who die and will be raised from their graves to accompany their Savior to heaven.
Paul writes about this, “For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first: Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord” (1 Thessalonians 4:16,17).
Other than Elijah and Moses that were taken to heaven, there was a special resurrection when Jesus was resurrected. The Bible says many of those who slept rose and appeared to others “And came out of the graves after his resurrection, and went into the holy city, and appeared unto many” (Matthew 27:53). These saints ascended to Heaven with Jesus but that was not a universal resurrection (Ephesians 4:8). So, there are some Christians and some saved people from this life who are in glory now – but generally speaking, the mass exodus is going to be when the Lord descends from Heaven at the second coming.
For more on this topic please check the following link: https://bibleask.org/bible-answers/112-the-intermediate-state/
In His service,