"The phrase first appeared in Nietzsche's 1882 collection The Gay Science (Die fröhliche Wissenschaft, also translated as "The Joyful Pursuit of Knowledge and Understanding"). However, it is most famously associated with Nietzsche's Thus Spoke Zarathustra (Also sprach Zarathustra), which is most responsible for making the phrase popular. " Check wikipedia for this detail . https://en.wikipedia.org/wiki/God_is_dead#:~:text=The%20phrase%20first%20appeared%20in,of%20Knowledge%20and%20Understanding%22).