Carl Jung was an atheist. Standard Jungians know this, but they do not say it outright.
Jung is like Richard Dawkins, Sam Harris, etc in that he does not believe in an external entity creator of the universe. Jung’s « God » is phenomenological, not theological, and he allows for many valid varieties of religious experience.
Sigmund Freud was a naive atheist, a scientistic thinker. Like Richard Dawkins, he saw no place for God in the physical universe.
Jung was an atheist in this sense too, only he was more psychological (or existential), as he used « God » as a name for the emergence of numinous events in the psychic process, so he wrote a « theogony », i.e. a genetic phenomenology of the formation, or « birth », of the God-image in the human psyche
From the notebooks of a self-experimentation, a psychological work in a literary and theogonic form was created (Sonu Shamdasani, Introduction to The Black Books).