When I say “biblical writers,” I am referring to the people of faith who developed an unproven, unprovable understanding of Someone they believed, in the words of Paul Tillich, to be the grounding of their being.
There’s lightning? That comes from God. There are plains and mountains and rivers as far as the eye can see? God’s gift.
God is mentioned but never described in the Bible. No one has seen the face of God, the Bible states repeatedly.
Philosophers have various versions of God: creator, prime mover or nonexistent.
People of faith have had gods and eventually God, whom they have not known, but whom their intuition told them was always there. In some ancient religious stories, the world is a dream of the Godhead, in others a secretion, in yet others dismembered parts of God dispersed in an early Big Bang-like event.
In our Judeo-Christian tradition, God is the eternal necessary being, indeed the only one whose essence is existence. God is. Period. God is the One who caused everything and everyone else to exist. Without God, nothing.
In Genesis we find one answer to the question of how God made something out of nothing, which is the correct and original English meaning of “create.”
We forget that. We pleasantly engage in a romantic poetry of thinking of ourselves as little gods, going about creating things, especially in art, music and literature. At best, if we are lucky or gifted, we reassemble things and ideas we have seen or heard of in an original way.
As to heaven and earth, to the ancients they were pretty a much a snow globe, or perhaps a water globe. There were the waters of the sea and by them the earth and the waters of the dome of the sky, from which hung stars, heavenly twinkling ornaments at night.
“And God said: Let there be a firmament made amidst the waters: and let it divide the waters from the waters. And God made a firmament, and divided the waters that were under the firmament, from those that were above the firmament, and it was so. And God called the firmament, Heaven; and the evening and morning were the second day. God also said: Let the waters that are under the heaven, be gathered together into one place: and let the dry land appear. And it was so done. And God called the dry land, Earth; and the gathering together of the waters, he called Seas. And God saw that it was good.” (Gen. 1:6-10)
Let’s not impose centuries of philosophies or 21st century science on authors who did not know either. Belief in divine creation need not be literal acceptance of the precise words of Genesis, whatever the original said.
The creation story is a myth. This does not mean it is false, but that it uses literary tools to convey beliefs that the storyteller holds dear for reasons that, at heart, can't be explained. That's why it's called faith.