Luke 21:11

“And there will be great earthquakes, and in many and various places famines and pestilences, and there will be terrors and great signs from heaven.”

And along with wars will come natural events, great earthquakes, famines, pestilences, terrors and portentous signs in the heavens. These will all be reminders that Christ is coming whenever they occur, but are not to be seen as evidence of His imminent return. Rather they are to be seen as evidence of God's continuing anger against the sin of man. Compare for ‘earthquakes' Isaiah 13:13; Isaiah 29:6; Haggai 2:6; Zechariah 14:4; Revelation 6:12; Revelation 8:5; and regularly. For famines (loimoi) and pestilences (limoi) (note the play on words) compare Ezekiel 14:12; Ezekiel 14:19; Ezekiel 14:21; Jeremiah 15:2; Amos 4:6. For portents in the heavens compare Isaiah 13:10; Isaiah 34:4; Isaiah 51:6; Ezekiel 32:7; Joel 2:10; Joel 2:31; Amos 8:9. Jesus had a wide background on which to draw. It is interesting that Josephus describes such signs and portents as having preceded the fall of Jerusalem, signs such as a ‘tailed star', or comet, which resembled a sword which stood over the city for a considerable time. Events like these are all represented in Revelation in terms of the horsemen on black and pale coloured horses (Revelation 6:5) followed by vivid effects in the heavens (Revelation 6:12).

Tacitus, a first century Roman historian, after referring to the horrors and calamities, and disasters and portents, of the period, went on to say ‘never has it been better proved, by such terrible disasters to Rome, or by such clear evidence, that the gods were concerned, not with our safety but with vengeance on our sins.' Thus he too saw the 1st century AD as a century of disasters. These included among others not only continued warfare, but also serious famines in the times of Claudius and Nero, a great earthquake in Phrygia in about 61 AD, and the later eruption of Vesuvius which buried Pompeii and neighbouring towns. It was fitting that it was in such a century that God sent His Son into the world.

We can see in these verses a picture of the whole history of nations. This is history as we know it, and there has been no century in which such things have not occurred, from the first to the last, including portents in the heavens, and a world which has seemed upside down. They are intended to be like a fire alarm practise, saying, ‘Be ready for when I come, even though you do not know when it will be'.