Lord how will we know of your coming again?

Jesus spoke saying, As it was in the days of Noah, so will it be in the days of the Son of man. They ate, they drank, they married, they were given in marriage, until the day when Noah entered the ark, and the flood came and destroyed them all.  Likewise, as it was in the days of Lot—they ate, they drank, they bought, they sold, they planted, they built, but on the day when Lot went out from Sodom fire and sulphur rained from heaven and destroyed them all — so will it be on the day when the Son of man is revealed.  On that day, let him who is on the housetop, with his goods in the house, not come down to take them away; and likewise let him who is in the field not turn back.  Remember Lot’s wife.  Whoever seeks to gain his life will lose it, but whoever loses his life will preserve it.  I tell you, in that night there will be two in one bed; one will be taken and the other left.  There will be two women grinding together; one will be taken and the other left.” Luke Chapter 17: 27-35