These verses do not describe the destruction of Jerusalem but the Tribulation at the end of the present age and the Second Coming that will follow it. The Second Coming is the climax of the Olivet Discourse.320
13:24-25 In contrast to the appearance of false Messiahs, the true Messiah will appear after the predicted Tribulation.321This is, of course, a reference to the Second Coming, not the Rapture.322The Book of Revelation gives further information about the celestial phenomena that will happen then (Rev. 6-18; cf. 2 Pet. 3:10). However the Old Testament prophets also predicted these things (Isa. 13:10; 24:23; 34:4; Ezek. 32:7-8; Joel 2:10, 30-31; 3:15; Amos 8:9). If we take the wars, earthquakes, and famines of verses 7-8 literally, we should probably understand these phenomena literally too.
13:26 Jesus described His return by referring to Old Testament prophecies of it (Dan. 7:13; Deut. 30:4; Zech. 2:6). The disclosure and triumph of Jesus are major emphases (cf. Rev. 19:11-16).323Jesus will no longer appear primarily as the Suffering Servant but as the glorified Son of Man.
13:27 Evidently Jesus will bring all the elect together. This implies the resurrection of Old Testament saints (Dan. 12:2) and Tribulation saints who have died (Rev. 6:9-11). Probably Christians, saints of the church age who have gone to heaven at the Rapture or death, will return with Him (1 Thess. 4:17). Saints living on the earth when Jesus returns will also assemble to Him (cf. Matt. 25). Jesus pictured all believers converging to Him at His second coming whether alive or dead, on earth or in heaven. He will become the universal center of attention, and then He will begin reigning. Unbelievers will not experience resurrection until the end of Jesus' millennial reign (Rev. 20:7-15).