Assuming Gen 1:1 describes an act of creation and is not a title: It’s striking that the Gen account begins with the creation of two realms rather than a single entity or realm. Hesiod says that there was one reality, chaos; Anaximander says “together were all things”; Thales claimed that water was the beginning.

But not Gen: Duality and difference does not arise from a prior unity. Difference is primordial in creation, as in God.