God is a God of purpose. That means He leaves nothing to chance and everything that He made has an intended reason for being here. This seems odd in an age such as our own which tends to leave so much up to chance or fate or the direction of the wind as they say, including our very own existence, but is that how the God of purpose works? What really is our reason for being here? Why does the sky exist? Why do clouds appear? Why do we have eyes, ears, hands, and feet? In the words of a curious three year old, "Why? Why? Why?!!!"
When God set up the Earth, He did so with purpose in mind and He did it in a purposefully, orderly fashion. First, at least we can assume, He set up Earth's foundations (the inner layers of the Earth) and Scripture would seem to indicate that He covered it with a watery deep (the tehowm as it's known in the Hebrew language), setting at its interface bars or doors - the basaltic ocean crust above the mantle. At some point during the laying of the foundations, He laid its "cornerstone," the chief stone upon which a structure is built (Job 38:6). They say the Earth has layers - a crust, mantle, outer and inner core. Are these the same foundations (notice the plural use of the word) that the Bible speaks about? Job 38:6 seems to imply that these foundations sank (or settled) down so-to-speak and when God laid Earth's cornerstone (it's core), the use of the word "laid" actually refers to the action of casting or throwing an object into place. Funny too is that scientists say Earth's inner core is a solid ball made out of a nickel-iron alloy which is basically a "stone" so-to-speak showing that the Bible revealed this fact before science ever got a foothold on it. Scientists call this sinking down of the various layers of the earth including its core (i.e. "cornerstone"), planetary differentiation. The great pressure of the deep and the overlying rock layers would help to trap the heat of the inner Earth and use it to power some of Earth's critical functions at a later time.
To make a home for the people He would create to inhabit it, He had to give them light and energy, the cycle of day and night, air and sky - a medium for sound waves to travel in, a layer to burn up foreign objects, the place where weather happens, where clouds are formed, an ocean of air for Earth's inhabitants to breathe. Those were just the first two days of His creation. Then on the third day, He began to build the actual structure for His created beings to live on, to eventually subdue with time, so He called for the waters to gather unto one place (a universal sea it seems; in scientific terms Panthalassa is the name given to the universal ocean that once surrounded the supercontinent of Pangea), then He let the dry land appear (terra firma, the place He called Earth, a single giant landmass - a supercontinent of sorts) to rise up through volcanic activity perhaps out of the watery chasms of the deep, from the inner portions of the Earth. He caused to come forth the green grass, the herbs of the field, the trees, fruit and within them the seeds which would carry the complete set of instructions for how to build future generations like themselves, the very mechanism by which genetics operates, a hint about this amazing structure called DNA, thousands of years before Mendel's discovery of it. These things would serve as food for Earth's inhabitants, means by which the creeping thing, the walking beings, the flying creatures would find their sustenance.
On the fourth day He called for the light-generating objects to appear - the sun and other stars along with the moon (which is not a light generator itself, but a reflector of light, a dim mirror so-to-speak) to appear to serve as signs (signals) to help cause various things to happen on Earth (you'll have to read my book to find out what these signs/signals could be and how they work), for the marking of time, and to help bring about the seasons among other things.
Next, on the fifth day, He called for the creatures that inhabit the sea and those that fly above the Earth to make their appearance, followed by the land dwellers on the sixth day, ending His work with the crown of His creation, a specially crafted, carefully designed being called man that was made in the image (the likeness) of Himself, consisting of body, soul, and spirit - a nod to God's existence of three in one, the Father, the Son, and His Holy Spirit. On that note He rested.
Just what constitutes a "day" in the Genesis 1 reference has hotly been debated. In case you aren't familiar, I'll briefly mention a few of these ideas below. For some, each day represents a literal 24 hour period of 7 days that happened some 6,000 - 10,000 years ago which represents the general Young Earth Creationist view (there are also Old Earth Creationists). For others, each day represents an age of indefinite time (the Day-Age view). Some believe that the creation days were literal 24 hour days, but each day and creation event were separated by undetermined amounts of time (the Intermittent Day view). Finally, some believe in a Gapview where a gap is present between Genesis 1:1 and Genesis 1:2.For those that hold to this latter theory, within the gap, there was an original creation wherein transpired the various ice ages, the age of the dinosaurs, etc. that was ruined by the fall of Satan whereby the earth itself became ruined and then restored by the creation events that followed in the remaining verses of Genesis 1. In determining which view is correct, it is best to see where the evidence best stacks up.
So now we see a glimpse of how God made the Earth a home for mankind and the other creatures that would live in it as Isaiah 45:18 states: "For thus saith the LORD that created the heavens; God himself that formed the earth and made it; he hath established it, he created it not in vain, he formed it to be inhabited [emphasis added]: I am the LORD; and there is none else." We see that He truly did establish everything that He made with specific, unique purposes in mind and this is only the tip of the iceberg of what the Bible says God has done!