Matt 24:23-26
23 Then if any man shall say unto you, "Lo, here is Christ, or there"; believe it not.
24 For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect.
25 Behold, I have told you before.
26 Wherefore if they shall say unto you, "Behold, He is in the desert"; go not forth: "behold, He is in the secret chambers"; believe it not.
KJV
Those deceived in Judea-Jerusalem claiming Christ has come there, won't be saying Jesus. They will think it is the Messiah of Old Testament Scripture. One of the definitions of the word "antichrist" in the Greek is the 'instead of, or in place of Christ'.