When I understood what role the concept plays in the dynamics and psychology of human relations.
'God' is a human projection originating from drives for power and domination, and for humans to be themselves masochistically dominated (the basic template is that of master-slave, whether it's God[master]>human[slave], or human+their specific version of god[master]>human-without-that-version-of-god[slave], etc).
'God' is the ultimate authority and power figure which both placates and compensates for the lack of such qualities in humans (the therapeutic function), and is used by individuals and groups to increases power and authority over others (the control function).
And the related concepts of heaven and hell are obviously all too human projections too, but more directly from the human subconscious, and embody the narcissistic and sadomasochistic fantasies which play out in that region of the human mind.
However, there still may be something which is responsible for everything (this universe) existing rather than nothing. Whether that thing is conscious or unconscious, a moral agent or not, beyond space and time or not, or has any recognisably psychological characteristics at all, is totally unknown. Maybe it's an n-dimensional alien supercomputer, or this universe is actually a tiny bubble on a higher dimensional ocean of metaphysical possibilities.
Maybe I just don't care anymore and better to be dead.