Mark 13

Mark 13:22:
​because false messiahs and false prophets will appear and produce signs and omens to deceive, if possible, the elect.

​It is interesting to note that the word translated "messiahs" or "prophets" was not just "teacher." Apparently, if there is not someone proclaiming some kind of "divinity," they will at least claim that which is false is true and that these claims will also affect the future. I see this kind of dogma in some of the sciences already, particularly with the issue of evolution. The evolution idea is being bought hook line and sinker by many churches.

Mark:13:32-37:
“But of that day and that hour knoweth no man, no, not the angels which are in heaven, neither the Son, but the Father. Take ye heed, watch and pray: for ye know not when the time is. For the Son of man is as a man taking a far journey, who left his house, and gave authority to his servants, and to every man his work, and commanded the porter to watch. Watch ye therefore: for ye know not when the master of the house cometh, at even, or at midnight, or at the cockcrowing, or in the morning: Lest coming suddenly he find you sleeping. And what I say unto you I say unto all, Watch.” 

​We do not know when Christ will return, but He tells us to watch for His coming.
The Bible lists several things to watch for — earthquakes, false Christs, wars, and rumors of wars are the most well-known. The gospel of Luke mentions signs in outer space, the nations of the earth facing problems with no solutions, and abnormally hostile weather (Luke 21:25).
Paul writes a list in 2 Timothy 3:1-7 that speaks of the attitudes and actions of people in the last days. Paul’s list describes people today so well that one must wonder if the end is much closer than we realize.
The vast majority of Christians believe the second coming comes in two phases — the rapture, then the actual return of Christ at the end of the Tribulation period.
The rapture is an event where Christ appears in the clouds and calls the saved out of the world. The most vivid description of the rapture is found in 1 Thessalonians 4:16-17, “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.” -Timothy Johnson