One of the major reasons that Jeremiah’s message would have been viewed so negatively in Judah was the presence of prophets who were prophesying lies. They were telling the king and the nation, You shall not serve the king of Babylon.
This brief summary of their message is a direct contradiction of Jeremiah’s message. These prophets were saying that the Lord would soon set Judah free of Babylonian rule, which implied the immanent downfall of Nebuchadnezzar. In Jeremiah 27:16–22, Jeremiah will expose the false beliefs that were giving rise to this false message.
Zedekiah and the nation are warned by Jeremiah not to listen to these prophets because the Lord did not send them and they are prophesying falsely in the Lord’s name. The preaching of the prophets and the believing of their message will lead to the exact opposite of what they were proclaiming. The Lord will in fact drive you out and you will perish, you and the prophets who are prophesying to you.
This is of course exactly what did happen (2 Kings 25:1–7).
14 Do not listen to the words of the prophets who are saying to you, ‘You shall not serve the king of Babylon,’ for it is a lie that they are prophesying to you.