What does Matthew 24:5 mean?
The disciples have responded to Jesus' dire prediction about the destruction of the temple (Matthew 24:1–2) with two questions. They have asked when judgment will fall on Jerusalem, what signs to expect for Jesus' return and the end of the age. As He so often does, Jesus chooses to provide additional information, rather than directly giving an answer. He begins by warning them about the time to come when He will be absent from them (John 16:5–7). They need to be diligent about not being fooled (Matthew 23:4).Many deceivers will come saying they are the Christ, the Messiah. Jesus does not mean that they will pretend to be Him, specifically. The disciples would know Him from another person. Instead, Jesus is saying that many will come who claim He was not, in fact, the Messiah—Jesus will have been executed by Rome by then (Matthew 16:21)—and that they are really the Christ. Jesus adds that many of these liars will be successful: numerous people will be taken in. Since Jesus is the only true path to the kingdom of heaven, those led astray will be led toward destruction.
History records examples of people who claimed to be the Promised One after Jesus' earthly ministry was over. One such false Messiah, Simon Bar Kokhba, failed in an attempt to revolt against Rome in 135 AD. Jesus does not want His followers to be caught in any such foolish deception.