Jesus strongly warns his disciples. They will meet people on their paths who will try to confuse them: Have you already seen that sign?
Or they say, We have heard that Jesus has been seen somewhere.
Know for sure, says Jesus, that these are pure lies. Do not let yourself be tempted to pay attention to them. Do not go along with people who say those things.
In the centuries after this urgent warning from Jesus, there have indeed been people who have presented themselves as a messiah, or who said that the kingdom of God had arrived.
Think for example of the actions of, among others, Thomas Müntzer in the sixteenth century. People arose with names like Enoch and David, who dreamed apocalyptic dreams and felt called, not by a slow reformation, but by a violent revolution, to bring about the kingdom of God.
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Jesus definitely finds it necessary to warn his followers of all times. That is why, later in Jerusalem, he repeats it emphatically: See that you are not led astray. For many will come in my name, saying, I am he! and, The time is at hand! Do not go after them
(Luke 21:8).
23 And they will say to you, ‘Look, there!’ or ‘Look, here!’ Do not go out or follow them.