John 13:19
I am telling you now before it happens, so that when it comes to pass, you will believe that I am He.

John 16:4-30, 31
But I have told you these things so that when their hour comes, you will remember that I told you about them. I did not tell you these things from the beginning, because I was with you. . . .

Matthew 24:24, 25
For false Christs and false prophets will appear and perform great signs and wonders that would deceive even the elect, if that were possible. . . .