Mark 13:29-33

So also, when you see these things taking place, you know that he is near, at the very gates. Truly, I say to you, this generation will not pass away until all these things take place. Heaven and earth will pass away, but my words will not pass away. “But concerning that day or that hour, no one knows, not even the angels in heaven, nor the Son, but only the Father. Be on guard, keep awake. For you do not know when the time will come.