Lol! I had a Christian friend who arrived at a philosophy class early one day and scrawled that on the blackboard. The professor was NOT pleased.
God is dead. God remains dead. And we have killed Him. How shall we comfort ourselves, the murderers of all murderers? What was holiest and mightiest of all that the world has yet owned has bled to death under our knives: who will wipe this blood off us? What water is there for us to clean ourselves?
It was not a statement of triumph but of mourning.
When you remove God you remove the underpinning of morality for everything. At that point who can say what is wrong? Who can say what is right? And despite the idea pushed by some that humans can be good without a underlying moral system we have proven repeatedly that we can not.