The Characters: Jesus, Peter, James, John, and Andrew (Mk. 13:3).
The Subject: 1) Christ's Second Coming and 2) the end of the world (Mt. 24:3). [Note: "world" is better translated "age." The Greek, αἰών (aiōn), in context, refers to the end of "The Times of the Gentiles" (Lk. 21:24)].
Jesus answers the second question first by describing "The Tribulation," a.k.a. "The Time of Jacob's Trouble" (Jer. 30:7) and "Daniel's Seventieth Week" (Dan. 9:27) (Mt. 24:3-28; Mk. 13:1-23; Lk. 21:5-26). The "Church Age" will end with born again believers being "caught up" to meet Christ in the air (Jn. 14:1-6; 1 Cor. 15:50-54; 1 Th. 4:16-17; Rev. 4:1). The Church is not mentioned after Revelation Chapter Three.
Ironically, Jesus in answering the first question, says that His Second Coming will mark the end of "The Tribulation" (Mt. 24:29; Mk. 13:24; Lk. 21:27). "Daniel's Seventieth Week" is actually seven years, which is divided into two halves (Dan. 9:27), each being 1260 days (Rev. 11:3) or 42 months (Rev. 11:2) or "a time, times, and half a time" (Dan. 12:7; Rev. 12:14). The division is marked by the Beast (Rev. 13) committing the Abomination of Desolation by declaring himself to be God (Dan. 9:27; 11:31; 12:11; Mt. 24:15; Mk. 13:14; Lk. 21:20).
During the first half of the Tribulation, Israel (partially blinded from the truth - Rom. 11:25) believes the Beast is their long-awaited Messiah (Dan. 9:27). When the truth about his identity is revealed by his committing the Abomination of Desolation, Israel flees into hiding for the remaining three and a half years (Mt. 24:15-28; Mk. 13:14-23; Lk. 21:20-26; Rev. 12:14).
It is at that time, Jesus returns and begins His 1000 year reign over this world; He will rule it with "a rod of iron" (Ps. 2:9; Rev. 19:15 - 20:15)! [Below: Christ's Second Coming - Mt. 24:29-30; see also Rev. 19:11-16)].
"Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken: And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory."