Oh man, yes!! This is the conversation I've been waiting to hear. You're absolutely correct. God being a literal, actual sky-deity of whatever tradition forms or portrays it, is ultimately irrelevant to the function of God (in this context I'm speaking of an image, a symbol, an archetype) and how it draws out of the subconscious the yet unrealized nature of who we are.
We come to know ourselves through God.
Why? Because in a theistic image of the Absolute, or the Infinite, there is an "I-Thou" relationship. A 2nd person perspective, which creates a relationship to ourselves, through our relationship to the other. This is how we function in normal daily interactions, where our relationship with and to the other, creates our own self-sense. So when it comes to the theistic view of God, God plays the role of the "Holy-Other". We lay ourselves down before this form of the Divine, we humble ourselves, we empty ourselves of ego and its striving and self-seeking. Only in this, in that moment of abandoning the small self, the egoic "I", do we begin to see that "me" beyond the ego. It is to say the least, liberating. That relationship moves that to one of freedom and equality, a marriage of the soul with the Divine, and the ego is transcended. It tells us of our Divine nature and Identity.
These are the roles of archetypes. To quote from Ken Wilber, whom I'm an avid admirer of his insights, this really expresses well that realization I came to in myself in moving away from identifying myself as an atheist.
"But this is not God as an ontological other, set apart from the cosmos, from humans, and from creation at large. Rather, it is God as an archetypal summit of one's own Consciousness. ... By visualizing that identification 'we actually do become the deity. The subject is identified with the object of faith. The worship, the worshiper, and the worshiped, those three are not separate'. At its peak, the soul becomes one, literally one, with the deity-form, with the dhyani-buddha, with (choose whatever term one prefers) God. One dissolves into Deity, as Deity - that Deity which, from the beginning, has been one's own Self or highest Archetype."
~Ken Wilber, Eye to Eye, pg. 85
The power of belief, of visualization, of faith in direct experience (not faith as a cognitive belief, but a faith of the entire being in abandoning itself to the unknown), is undeniably powerful in individual practice. But it must be realized in actual practice, and not just some doctrinal statement of faith. I see those as comparable to the training wheels on a bicycle that serve only to show you what balance is supposed to look or feel like, but that you will not truly know until your ride under your own sense of balance. At which point, those training wheels need to come off or they become a hindrance to flow. As the Buddha said, "To insist upon a spiritual practice that served you in the past, is to carry the raft upon your back after you've already crossed the river".
It's my view that atheism, and what it was for me and what role it played was to break off the training wheels in order for me to ride freely. But atheism, like any screwdriver that helped you unloosen something, shouldn't become your tool for life. Now, I'm free to believe, or not believe, or whatever serves the end which is growth into a knowledge of the true Self, and through this Knowledge to love others as myself.