Here is the text. Mark 13
13:19 For in those days shall be affliction, such as was not from the beginning of the creation which God created unto this time, neither shall be.
13:20 And except that the Lord had shortened those days, no flesh should be saved: but for the elect's sake, whom he hath chosen, he hath shortened the days.
13:21 And then if any man shall say to you, Lo, here is Christ; or, lo, he is there; believe him not:
13:22 For false Christs and false prophets shall rise, and shall shew signs and wonders, to seduce, if it were possible, even the elect.
13:23 But take ye heed: behold, I have foretold you all things.
This is also taught in the books of Matthew, Luke, and Revelation and it is going on now.
Y'shut Messiah told us all things regarding these times so we would not be deceived.