The creation account reads:
1 In the beginning God created the heaven and the earth.
2 And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
3 And God said, Let there be light: and there was light.
4 And God saw the light, that it was good: and God divided the light from the darkness.
5 And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.
6 And God said, Let there be a firmament in the midst of the waters, and let it divide the waters from the waters.
7 And God made the firmament, and divided the waters which were under the firmament from the waters which were above the firmament: and it was so.
8 And God called the firmament Heaven. And the evening and the morning were the second day.
9 And God said, Let the waters under the heaven be gathered together unto one place, and let the dry land appear: and it was so.
10 And God called the dry land Earth; and the gathering together of the waters called he Seas: and God saw that it was good.
11 And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it was so.
12 And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind: and God saw that it was good.
13 And the evening and the morning were the third day.
14 And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years:
15 And let them be for lights in the firmament of the heaven to give light upon the earth: and it was so.
16 And God made two great lights; the greater light to rule the day, and the lesser light to rule the night: he made the stars also.
17 And God set them in the firmament of the heaven to give light upon the earth,
18 And to rule over the day and over the night, and to divide the light from the darkness: and God saw that it was good.
19 And the evening and the morning were the fourth day. (Genesis 1)
Before there was a sun or moon, there was light. Before the sun existed, “darkness was upon the face of the deep.” These mysteries need not be confusing. Light includes what we see emanating from the sun and reflecting from the moon, but it is much greater than that.
Matter is eternal. It cannot be created or destroyed. It can be organized together, or separated. Matter differs in how it reacts to light. Some matter responds to a great degree, and some to a lesser degree, and the manifestations of that response are varied.
All of creation is designed to be a mechanism for increasing the material response to light. God’s purpose is to provide the environment and experiences necessary to bring about the greatest possible material response to light.
The creation account shows how he does this. He created the heaven and the earth by bringing together matter that was previously dissociated. His influence provided a means for the matter to react to a greater extent. Then he invited the matter to recognize and react to the light. Some of it did, but not all, and he was able to divide the responsive matter from the matter that was not responsive. The “days” of creation were not rotations of our planet around a star. What we call an evening and a morning are merely signs that give a figure of a much greater process. Each creation day is a step towards greater light consisting of an “evening” where the darkness of a lack of awareness of limitations is replaced by a “morning” of God’s providing a means for greater response to light, followed by his inviting matter to respond to a greater degree, followed by his division of the newly differentiated matter.
This process did not end with the creation of the sun and moon. Or with man. Everything that God does follows this pattern. Everything serves his plan.
The whole point of the gospel is to increase the response of matter to light. “For the commandment is a lamp; and the law is light; and reproofs of instruction are the way of life.” (Proverbs 6:23)