Why did Jesus preach "Repent" in Matthew 4:17?
Jesus preached "Repent" in Matthew 4:17 because the King was present and ready to set up His kingdom. The call to repentance announced that the King had arrived and the kingdom was ready to be established, while the Jewish nation would continue to reject it.
Les explains that Matthew 4:17 marks the point from which Jesus began to preach and say, "Repent." The reason given is that the King was there, ready to set up His kingdom. This fit the whole format coming out of the Old Testament. Yet the Jew was going to continue to reject it, and then God reveals the mysteries.
Matthew 4:17
From that time Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand.