The first three days of creation describe the forming of the earth, and the second three describe its filling. Together they remedy earth's initial condition of being “without form and void.” This is immediately apparent as we see that day one describes the creation of light, which is then matched by day four, which describes the filling of earth with light. Moses is saying that the sun, moon, and stars are not gods, but God's creations! With just a mere word—the expression of God's will—the solar system was set like a jeweled watch in the midst of the universe. With a word He made the galaxies and all that inhabit them.