Ancient kings might kill a messenger that brought them bad news.  When a messenger brings messages that we don’t want to hear we try to discredit the messenger in an attempt to reject the message.  Look at Jesus.  False witnesses spoke against him; some demonized Him.  They attacked His lowly origins; they put Him down because of His region of the country.  All of these are old tactics that really never go away; they only return in new forms.  These tactics were to prevent other persons from listening to His message.  Evaluate a message based on its truth, not if you like it; truth is truth; a true message will survive after the messenger is dead and gone.

“As it is, you are determined to kill me, a man who has told you the truth that I heard from God.” John 8:40a (NIV)