At the turn of the millenium a lie was circulating that Iraq had weapons of mass distruction and were preparing to use them. The truth was they didn't have weapons of mass destruction and they were content with the reality of retaliation when they cross another countries borders. Not long after that, America and the UK invaded Iraq. They were invading a sovereign country that did nothing to them because of lies.
Every murderer lies to themselves, they tell themselves that it is ok to kill someone for what ever reason, it's not ok, it is a crime. It is never ok to kill another human being, even if they did something horrible to you in the past. When the murderer kills, they cover up their crime and lie about what they have done.
If someone says something with no evidence or proof then they are most likely lying and should be condemned. If someone says something and you think is a lie then you should speak out and rebuke that lie because it will open a doorway to wickedness.