What does Mark 13:26 mean?
Revelation 19 gives a more detailed description of Jesus' "great power and glory." He will arrive on a white horse, His eyes will be like fire and His robe will be dipped in blood. His army will follow on white horses. A sharp sword will come from His mouth and will destroy nations. He will bring the fury and wrath of God (Revelation 19:11–16). While the rapture will remove believers from the earth, during Jesus' second coming, unbelievers will be destroyed and those who came to trust Christ during the tribulation will remain."Son of Man" is one of the more common ways Jesus describes Himself. Daniel tells how the Ancient of Days will give "one like a son of man" everlasting dominion, glory, and a kingdom over all the peoples, nations, and languages (Daniel 7:13–14). Jesus' use of this title has confused the disciples about what the Messiah has come to do. They can understand how Jesus can be the Son of Man who is given a kingdom by God, but they can't understand how that same victorious figure ties in with Isaiah 53's "Suffering Servant" who is despised and rejected by men. Jesus gives a clue here: the Son of Man will not come into His glory until the end times. Between now and then, the Suffering Servant must die (Mark 8:31; 9:31; 10:33–34).
God's presence is often accompanied by clouds. A cloud guided the Israelites by day (Exodus 13:21). God protected Moses from His glory with a cloud (Exodus 19:9). And God appeared during Jesus' transfiguration in a cloud (Mark 9:7). God seems to use our literal heavens as a metaphor for the spiritual heavens in which He lives. Clouds, then, act as a kind of threshold between the realms.
This wording, combined Mark 13:29, is similar to the rapture in that Jesus will descend from heaven and gather His followers (1 Thessalonians 4:15–17). There are at least three identifying differences between the rapture and this, the second coming. Nothing needs to happen in human history before the rapture, but the entire tribulation must pass before Jesus' second coming. The rapture will take place in a single moment with no fanfare (1 Corinthians 15:50–54), unlike the spectacle of the second coming which is described here. And during the rapture, Jesus will stay in the clouds (1 Thessalonians 4:17), while the second coming marks His physical return to earth (Zechariah 14:4).