In Jesus' foretelling of the time just before His return, the days will be so perilous that unless God had put a limit on the number of the days, no flesh would be saved. Yet for the sake of the elect, a limit has already been placed. Luke's phrase, the days of vengeance, that all things which are written may be fulfilled, is parallel to the statement that unless those days were shortened, no flesh would be saved. The overwhelming end-time peril is vengeance rather than technology. The time when mankind's survival hangs in the balance parallels the prophesied time of divine vengeance in the lead-up to Christ's return. At that time, He will take His vengeance against all flesh, first Israelite and then Gentile. Because of the hardness of the human heart, that day will manifest primarily in wrath, though there will be mercy for the elect's sake.

Matthew 24:22 says that unless those days were shortened, no flesh would be saved, and for the elect's sake they will be shortened. Herbert Armstrong cited this verse as the most provable sign that we live in the last days. Other translations render "no flesh would be saved" as "not a soul would be saved alive," "no living thing could survive," and "no human being would endure and survive." The verse therefore means that the last days will be marked by mankind's ability to annihilate every living thing on earth. If God does not intervene, the nations will fight until all life perishes, and He will cut those days short for the sake of His elect. This ability exists today as it never has before. Only since the atomic bomb in 1945 and the hydrogen bomb in 1952 has man had the knowledge and means to wipe himself out. The Cold War left stockpiles able to erase life from the earth many times over, and the reduced arsenals of the five major nuclear powers, along with chemical, biological and neutron weapons, still far exceed what is needed to kill all flesh. Man has never failed to use a weapon he invented, so this one sign proves conclusively that these are the last days.