God would soon (during the sixth day) place a creature created in his own image upon the earth. Years later his only Son would be born upon this planet and die upon it. Furthermore, the King of kings will someday once again return to this earth.
All ancient civilizations worshiped the sun. It gave them light and warmth. But God wanted his people to know that light and life come from him—that the earth existed before the sun, and that he created both. Dr. John Whitcomb considers why God created celestial bodies: But if the sun, moon, and stars are not ultimately essential to the earth’s existence, then why did God create them? Three basic reasons are listed in Genesis 1:14. They are for lights, for seasons (a calendar), and for signs.
As lights, they replaced the special and temporary light of the early days.
As a calendar, dividing seasons, days, and years, they enable men to plan their work accurately into the distant future, thus reflecting the purposive mind of God.
As signs, they teach and ever remind men of vastly important spiritual truths concerning the Creator.
David learned from the heavens the transcendence of God and his own comparative nothingness. “When I consider the heavens, the work of Thy fingers, the moon and the stars which Thou hast ordained, what is man that Thou art mindful of him?” (Ps. 8:3). The Apostle Paul insisted that men are utterly without excuse for their idolatry. (The Early Earth, pp. 58–59)