When will some Christians realize that they don't know that we are in the "last days"?

They won't. One of the supervisors in my department keeps droning on about "the end times." Fortunately, she's not MY supervisor.

It's true that nobody will know for certain that we have arrived at the END of the 'last days' until Jesus is seen descending from Heaven with hosts of angels, in great glory.

But the 'last days' is a period of time, which had a particular beginning that is marked in history, and which will have a particular ending, also marked in history. Its beginning? Let non-believer H.G. Wells advise you:

"As a historian, this penniless preacher from Nazareth is irrevocably the very centre of history."

The Bible identifies historic events based on Jesus Christ as the beginning of a period that it calls "the last days". Jesus deliberately left His disciples expecting to see the end of "the last days" within their generation. But He also told them that He would leave for a long period of time before returning in glory. And His return would be like a thief in the night. See some of His parables for that. But if you are just out to dismiss what the Bible says about the last days, you won't.

But like the man walking the street with a billboard saying "The End Is Nigh!", don't forget it couldn't be a joke unless there really was such a possibility as 'the end'. Don't let the false prophets make you lose sight of that.

The problem for those who treat it as a joke is that, when it happens, it will be too late for them. That's why Christians keep warning about a future end of 'the last days'. It could happen any time. Don't be caught out.

Last Days

The Bible uses the expression "last days" to refer to the concluding time period leading up to a divinely appointed execution that marks the end of a system of things. The Jewish system with its worship built around the temple in Jerusalem experienced its last days from 33 to 70 C.E. What occured then was pictorial of what would be experienced in a greatly intensified way and on a global scale at a time when all nations would be facing the execution of judgment decreed by God. The present wicked system of things, which extends worldwide, entered its last days in 1914, and some of the generation alive then will also be on hand to witness its complete end in the "great tribulation".

There is always talk of "end times" by religious nuts. They totally ignore the fact that we are living in the most peaceful period in world history. And that is even despite the troubles in the Middle East.

So "claiming" things in conjecture causes you some sensitivity? Hm. That's rough. Have a milk shake.

@Here you go! Now please remember how easily these such disputes are resolved ongoing. And keep a milk shake machine handy. Cheers!