The existence of God is a prior tacit assumption. The conscious manifestation of God as a person is for the most part lacking in the normal interaction we experience, especially in common with other limited personhoods, and therefore usually viewed as a mere list of principles or axioms. But the god-like nature of this universal rule-set is a suppressed notion of rationalistic atheism.
I necessarily reference God-like mind objects in accessing my own awareness. The total irreducible integrated object set is an intuitively cross-assumed system, in many ways indistinguishable from a single mind.
The total set of assumptions we use to be aware of reality is treated as the God of mind. Reason communicates through the statements that make up its definition, assumptions, and implications.
We reference our ultimate ruling factors as a single interrelated and self-supporting system, and therefore God is a single being, in addition to the fact that it would be impossible to distinguish between two or more such ultimate beings because of the absence of positable differences.