The "murder" of God meant that man was left to create his own meaning, his own morality, and to learn to live without hope. Man's existential predicament would inevitably lead him to despair.
Nietzsche foresaw all this, but most men of his age did not. In their exuberance and rejoicing over their "assassination of God" and the liberation they were sure their deed had brought them, they failed to grasp that when God "died" with Him died any hope of transcendent purpose and any solid ground for right and wrong.
Nietzsche expressed this failure in a parable he included in his book The Gay Science. It's called the Parable of the Madman:
Have you not heard of that madman who lit a lantern in the bright morning hours, ran to the marketplace, and cried incessantly: "I seek God! I seek God!" -- As many of those who did not believe in God were standing around just then, he provoked much laughter. Has he got lost? asked one. Did he lose his way like a child? asked another. Or is he hiding? Is he afraid of us? Has he gone on a voyage? emigrated? -- Thus they yelled and laughed.The madman carried a lantern in the daylight because darkness was imminent. Man has become unmoored, like the earth unchained from the sun. Cold despair settles upon us as we plunge in all directions, adrift in nothingness. We are haunted by the sense that all is becoming colder.
The madman jumped into their midst and pierced them with his eyes. "Whither is God?" he cried; "I will tell you. We have killed him--you and I. All of us are his murderers.
But how did we do this? How could we drink up the sea? Who gave us the sponge to wipe away the entire horizon? What were we doing when we unchained this earth from its sun? Whither is it moving now? Whither are we moving? Away from all suns? Are we not plunging continually? Backward, sideward, forward, in all directions? Is there still any up or down? Are we not straying, as through an infinite nothing? Do we not feel the breath of empty space? Has it not become colder? Is not night continually closing in on us? Do we not need to light lanterns in the morning? Do we hear nothing as yet of the noise of the gravediggers who are burying God? Do we smell nothing as yet of the divine decomposition?
Gods, too, decompose. 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? What festivals of atonement, what sacred games shall we have to invent?
Is not the greatness of this deed too great for us? Must we ourselves not become gods simply to appear worthy of it? There has never been a greater deed; and whoever is born after us -- for the sake of this deed he will belong to a higher history than all history hitherto."
Here the madman fell silent and looked again at his listeners; and they, too, were silent and stared at him in astonishment. At last he threw his lantern on the ground, and it broke into pieces and went out. "I have come too early," he said then; "my time is not yet. This tremendous event is still on its way, still wandering; it has not yet reached the ears of men. Lightning and thunder require time; the light of the stars requires time; deeds, though done, still require time to be seen and heard. This deed is still more distant from them than most distant stars -- and yet they have done it themselves.
It has been related further that on the same day the madman forced his way into several churches and there struck up his requiem aeternam deo. Led out and called to account, he is said always to have replied nothing but: "What after all are these churches now if they are not the tombs and sepulchers of God?"
Nietzsche's lantern-carrying madman is an interesting and perhaps intentional counterpoint to another lantern-carrier depicted c.1854 by the artist Holman Hunt.
Hunt's lantern-carrier, unlike Nietzsche's, did not bring despair, but hope. He did not wipe out the horizon we use to navigate through life but rather gave life direction and meaning. Nor did he set us adrift in an infinite nothingness, but set our feet on the solid ground of objective, transcendent reality:
We might suppose that Nietzsche's lantern-carrier was driven mad by the consequences that he foresaw following upon the murder of Hunt's lantern-carrier.